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MIC3001 fom management ic with internal calibration consider mic3002 for new designs mlf and micro leadframe are registered trademarks of amkor technology. micrel inc. ? 2180 fortune drive ? san jose, ca 95131 ? usa ? te l +1 (408) 944-0800 ? fax + 1 (408) 474-1000 ? http://www.micre l.com august 2004 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 general description the MIC3001 enables the implementation of sophisticated, hot-pluggable fiber optic transceivers with intelligent laser control and an internally calibrated digital diagnostic monitoring interface per sff-8472. it essentially integrates all non-datapath functions of an sfp transceiver into a tiny (4mm x 4mm) mlf ? package. it also works well as a microcontroller peripheral in transponders or 10gbps transceivers. a highly configurable automatic power control (apc) circuit controls laser bias. bias and modulation are temperature compensated using dual dacs, an on-chip temperature sensor, and nvram look-up tables. a programmable internal feedback resistor provides unprecedented dynamic range for apc. controlled laser turn-on facilitates hot plugging. an analog-to-digital converter converts the measured temperature, voltage, bias current, transmit power, and received power from analog to digital. an eepot provides front-end adjustment of rx power. each parameter is compared against user-programmed warning and alarm thresholds. analog comparators and dacs provide high-speed monitoring of received power and critical laser operating parameters. data can be reported as either internally calibrated or externally calibrated. an interrupt output, power-on hour meter, and data- ready bits add user friendliness beyond sff-8472. the interrupt output and data-ready bits reduce overhead in the host system. the power-on hour meter logs operating hours using an internal real-time clock and stores the result in nvram. communication with the MIC3001 is via an industry standard 2-wire serial interface. nonvolatile memory is provided for serial id, configuration, and separate oem and user scratchpad spaces. two-level password protection guards against data corruption. features ? apc or constant-current laser bias ? turbo mode for apc loop start-up and shorter laser turn on time ? supports multiple laser types and bias circuit topologies ? drives external low-cost bjt for laser bias ? integrated digital temperature sensor ? temperature compensation of modulation, bias, and fault levels via nvram look-up tables ? direct interface to sy88932, sy88982, sy89307 and other drivers ? nvram to support gbic/sfp serial id function ? user writable eeprom scratchpad ? diagnostic monitoring interface per sff-8472 ? monitors and reports critical parameters: temperature, bias current, tx and rx optical power, ? s/w control and monitoring of txfault, rxlos, rateselect, and txdisable ? internal or external calibration ? eepot for adjusting rx power measurement ? power-on hour meter ? interrupt capability ? extensive test and calibration features ? 2-wire i 2 c compatible serial interface ? sfp msa and sff-8472 compliant ? 3.0v to 3.6v power supply range ? 5v-tolerant i/o ? 4mm x 4mm 24-pin mlf ? package applications ? sff/sfp optical transceivers ? sonet/sdh transceivers and transponders ? fibre channel transceivers ? 10gbps transceivers ? free space optical communications ? proprietary optical links
micrel, inc. sy89835u august 2004 2 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 ordering information part number package type junction temp. range package marking lead finish MIC3001bml 24-pin mlf ? ?45c to +105c 3001 sn-pb MIC3001bmltr (1) 24-pin mlf ? ?45c to +105c 3001 sn-pb MIC3001gml 24-pin mlf ? ?45c to +105c 3001 with pb-free bar-line indicator pb-free nipdau MIC3001gmltr (1) 24-pin mlf ? ?45c to +105c 3001 with pb-free bar-line indicator pb-free nipdau note: 1. tape and reel.
micrel, inc. MIC3001 august 2004 3 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 contents general description ............................................................................................................................... ....................... 1 applications ............................................................................................................................... .................................... 1 ordering information ............................................................................................................................... ..................... 2 pin configuration ............................................................................................................................... ........................... 7 pin description ............................................................................................................................... ............................... 7 absolute maximum ratings ............................................................................................................................... .......... 9 operating ratings ............................................................................................................................... .......................... 9 electrical characteristics ............................................................................................................................... .............. 9 timing diagram ............................................................................................................................... ............................ 14 address map ............................................................................................................................... ................................. 15 block diagram ............................................................................................................................... .............................. 17 mic3000 capability ............................................................................................................................... ....................... 17 analog-to-digital conver ter/signal m onitoring.................................................................................. ........................ 17 internal/external calibration.................................................................................................. .................................... 19 a/ external calibra tion ........................................................................................................ ...................................... 19 voltage ............................................................................................................................... ................................... 19 temperature ............................................................................................................................... .......................... 19 bias current ............................................................................................................................... ........................... 19 tx power ............................................................................................................................... ............................... 19 rx power ............................................................................................................................... ............................... 20 b/ internal calibration ............................................................................................................................... .................. 20 c/ adc result registers reading ............................................................................................................................. 22 rxpot.......................................................................................................................... ............................................ 22 laser diode bi as cont rol ....................................................................................................... ................................... 22 laser modulati on cont rol....................................................................................................... ................................... 23 power on and las er start-up.................................................................................................... .............................. 24 fault comparators .............................................................................................................. ...................................... 25 shdn and txfin ................................................................................................................. .................................... 26 temperature me asurement ........................................................................................................ .............................. 26 diode f aults ................................................................................................................... ........................................... 26 temperature co mpensation ....................................................................................................... .............................. 26 alarms and warn ing fl ags....................................................................................................... ................................. 31 control and status i/o ......................................................................................................... ..................................... 31 system timing ............................................................................................................................... .............................. 32 warm resets .................................................................................................................... ........................................ 35 power-on ho ur meter............................................................................................................ ................................... 35 test and calibr ation features .................................................................................................. ................................ 35 serial port operation .......................................................................................................... ...................................... 36 page wr ites .................................................................................................................... .......................................... 36 acknowledg e polling............................................................................................................ ..................................... 37 write protection and data se curity............................................................................................. .............................. 37 oem password ............................................................................................................................... ...................... 37 user password ............................................................................................................................... ...................... 37 detailed register descriptions ............................................................................................................................... ... 38 alarm threshold registers ............................................................................................................................... ......... 38 warning threshold registers ............................................................................................................................... ..... 43 adc result registers ............................................................................................................................... .................. 49
micrel, inc. MIC3001 august 2004 4 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 alarm flags ............................................................................................................................... ................................... 52 warning flags ............................................................................................................................... ............................... 53 applications information ............................................................................................................................... ............. 69 controlling laser diode bias ............................................................................................................................... ...... 69 choosing c comp ............................................................................................................................... ......................... 70 measuring laser bias current ................................................................................................... ............................... 70 interfacing to laser drivers................................................................................................... ................................... 70 sy88912 3.3v 3.2gbps sone t/sdh lase r driv er .................................................................................... ............. 71 modulation curr ent ............................................................................................................. ...................................... 71 sy88932 3.3v 3.2gbps sone t/sdh lase r driv er .................................................................................... ............. 71 sy89307 5.0v/ 3.3v 2.5g bps vcsel driver ........................................................................................ ................... 72 laser drivers programm ed via a sink current .................................................................................... ..................... 72 drivers with m onitor outputs................................................................................................... .................................. 72 shutdown output ................................................................................................................ ...................................... 72 temperature sensing ............................................................................................................ ................................... 73 remote sensing ................................................................................................................. ...................................... 73 minimizing errors ............................................................................................................................... ......................... 73 self-hea ting ................................................................................................................... ........................................... 73 series resistance with exte rnal temperat ure sensor ............................................................................. ................ 74 xpn filter capacit or selection ................................................................................................. ................................ 74 xpn layout cons iderations...................................................................................................... ................................ 74 layout consi derations .......................................................................................................... .................................... 75 small form-factor pluggable (sfp) transceivers ............................................................................................... 75 power s upplies ................................................................................................................. ........................................ 75 using the MIC3001 in a 5v system............................................................................................... ........................... 75 package information ............................................................................................................................... .................... 76
micrel, inc. MIC3001 august 2004 5 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 list of figures figure 1. MIC3001 block diagram ................................................................................................ ...................................................17 figure 2. analog-to-digit al converter bl ock di agram............................................................................ ...........................................18 figure 3. rxpot block di agram .................................................................................................. ...................................................22 figure 4. MIC3001 apc and modulation control blo ck diagram .................................................................... ................................22 figure 5. programmabl e feedback resist or....................................................................................... .............................................22 figure 6. transmitter configurati ons supported by MIC3001 ..................................................................... ....................................23 figure 7. v mod configured as voltag e output with gain ....................................................................................... ..........................23 figure 9. fault co mparator logic............................................................................................... ......................................................25 figure 10. satura tion detector ................................................................................................. ........................................................26 figure 11. rxlos co mparator logic .............................................................................................. ................................................26 figure 12. examples of lutoff o peratio n........................................................................................ .............................................29 figure 13. temperature compensati on exam ples................................................................................... ........................................30 figure 14. control and status i/o logic ........................................................................................ ...................................................32 figure 15. transmi tter on-off timing ........................................................................................... ................................................32 figure 16. initialization timi ng with txdisabl e asse rted ....................................................................... .......................................32 figure 17. initialization timing with txdisable not asse rted ................................................................... .....................................33 figure 18. loss-of-sign al (los) timing......................................................................................... ..................................................33 figure 20. successfully clear ing a fault condition............................................................................. .............................................34 figure 21. unsuccessful atte mpt to clear a fault ............................................................................... .............................................34 figure 22. write byte protocol ................................................................................................. ........................................................36 figure 23. read byte protocol .................................................................................................. .......................................................36 figure 24. read_w ord prot ocol.................................................................................................. .....................................................36 figure 25. four-byte page_white protocol....................................................................................... ...............................................37 figure 26. example apc circ uit for common- cathode tosa......................................................................... ................................69 figure 27. example apc circ uit for common anode tosa........................................................................... .................................69 figure 28. slew rate vs. c comp v alue ......................................................................................................................... ....................70 figure 29. open loop unity-gain bandwidth vs. c comp .................................................................................................................70 figure 31. controlling the sy88932 modula tion cu rrent.......................................................................... ........................................71 figure 32. controlling the sy89307 modula tion cu rrent.......................................................................... ........................................72 figure 33. controlling the modulati on current via a sink current .............................................................. .....................................72 figure 34. redundant switch ci rcuits ........................................................................................... ...................................................73 figure 35. guard traces and kelvin re turn for remote therm al di ode............................................................ .............................75 figure 36. typical sfp cont rol and status i/o signal ro uting (not to scale) ................................................... ..............................75 figure 37. power supply routing and bypassing .................................................................................. ..........................................75
micrel, inc. MIC3001 august 2004 6 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 list of tables table 1. MIC3001 address map, serial address = a0 h ................................................................................................ 15 table 2. MIC3001 address map, serial address = a2 h ................................................................................................ 15 table 3. temperature compensati on tables, serial address = a4 h ............................................................................ 15 table 4. oem configuration re gisters, serial address = a6 h ...................................................................................... 16 table 5. a/d input signal ranges and re solutions............................................................................... ....................... 18 table 6. v aux input signal ranges and resolu tions........................................................................................... .......... 18 table 7. lsb values of offset coefficients ..................................................................................... .............................. 20 table 8. internal calibration c oefficient memory map ? pa rt i .................................................................. ................... 21 table 9. internal calibration c oefficient memory map ? pa rt ii ................................................................. ................... 21 table 10. shutdown state of sh dn vs. configuration bits ....................................................................... .................. 24 table 11. shutdown state of v bias vs. configur ation bi ts............................................................................................ 24 table 12. shutdown state of v mod vs. configur ation bi ts............................................................................................ 24 table 13. temperature compensation look -up tables, serial address i2cadr + 4 h ............................................... 27 table 14. apc temperature compensation look-up table, serial address 12c adr+4 h ......................................... 28 table 15. v mod temperature compensation look-up table, serial address 12c adr+4 h ........................................ 28 table 16. i bias comparator temperature compensation loo k-up table, serial address 12c adr+4 h ...................... 28 table 17. bias current high alarm temperature compensation table, serial address 12c adr+4 h ....................... 28 table 18. range of temperature co mpensation tabl e vs. lutoff.................................................................. ........ 29 table 19. mic3 001 ev ents....................................................................................................... ..................................... 31 table 20. power-on hour meter result format .................................................................................... ....................... 35 table 21. test and di agnostic features ......................................................................................... .............................. 35 table 22. typical values for c comp ............................................................................................................................... 70 table 23. control range of sy88912 modulation cont rol circ uit ................................................................. .............. 71 table 24. transistors suitable for use as re mote diodes ....................................................................... ................... 73 table 25. contributor s to self -heating......................................................................................... ................................. 74
micrel, inc. MIC3001 august 2004 7 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 pin configuration 24-pin mlf? pin description pin number pin name pin function 1 fb analog input. feedback voltage for the apc loop op-amp. polarity and scale are programmable via the apc configuration bits. connect to v bias if apc is not used. 2 vmpd analog input. multiplexed a/d converter input for monitoring transmitted optical power via a monitor photodiode. in most applications, vmpd will be connected directly to fb. the input range is 0 - v ref or 0 - v ref /4 depending on the setting of the apc configuration bits 3 gnda ground return for analog functions. 4 vdda power supply input for analog functions. 5 vild? analog input. reference terminal for the mu ltiplexed pseudo-differential a/d converter inputs for monitoring laser bias current via a s ense resistor (vild+ is the sensing input). tie to v dd or gnd to reference the voltage sensed on vild+ to v dd or gnd respectively. limited common-mode voltage rang e, see ?applications information? section for more details. 6 vild+ analog input. multiplexed a/d input for monitoring laser bias current via a sense resistor (signal input); accommodates inputs referenced to v dd or gnd (see pin 5 description). limited common-mode voltage rang e, see ?applications information? section for more details. 7 shdn (txfin) digital output; programmable polarity. when us ed as shutdown output (shdn), asserted at the detection of a fault cond ition that can be used to activate a second series transistor in the laser current path, enhancing prot ection against single-point failures. when programmed as txfin, it is an input for exte rnal fault signals to be ored with the internal fault sources to drive txfault. 8 shdn (txfin) analog input. multiplexed a/d converter input for monitoring received optical power. the input range is 0 to v ref . a 5-bit programmable eepot on this pin provides for coarse calibration and ranging of the rx power measurement. 9 xpn analog input/output. optional connection to an external pn junction for sensing temperature at a remote location. the zone bit in oemcfg1 determines whether temperature is measured using the on-ch ip sensor or the remote pn junction. 10 txfault digital output; open-drain. a high level indicates a hardware fault impeding transmitter operation. the state of t his input is always reflected in the txflt bit.
micrel, inc. MIC3001 august 2004 8 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 pin description pin number pin name pin function 11 txdisable digital input; active high. the transmitter is disa bled when this line is high or the stxdis bit is set. the state of this input is always reflected in the txdis bit. 12 data digital i/o; open-drain. bi-directional serial data input/output. 13 clk digital input; serial bit clock input. 14 vin if bit 4 (ie) in usrctl register is set to 0 (default), this pin is configured as analog input. if ie bit is set to 1, this pin is configured as open-drain output. analog input: multiplexed a/d input for monitoring supply voltage. 0v to 5. 5v input range. open-drain output: outputs the internally generated interrupt signal /int. 15 rsin digital input; rate sele ct input; ored with rate select bit to determine the state of the rsout pin. the state of this pin is always reflected in the rsel bit. 16 gndd ground return for digital functions. 17 nc no connection. this pin is used for test purposes and must be left unconnected. 18 vddd power supply input for digital functions. 19 rxlos digital output; active-high/open-drain. indicate s the loss of the received signal as indicated by a level of received optical power below the programmed rxlos comparator threshold; may be wire-ored with external signals. low indicates normal operation. rxlos is de- asserted when vrx > losfltn. the los bit ref lects the state of rxlos whether driven by the MIC3001 or an external circuit. 20 rsout (gpo) digital output. open-drain or push-pull. when used as rate select output, this output is controlled by the srsel bit ored with rsin input and is open drain only. when used as a general-purpose, non-volatile output, it is controlled by the gpo configuration bits in oemcfg3. 21 comp analog output, compensation te rminal. connect a capacitor between this pin and gnda or v dda with appropriate value to tune the apc loop time constant to a desirable value. 22 vbias analog output. buffered dac output capable of sourcing or sinking up to 10ma under control of the apc function to drive an extern al transistor for laser diode d.c. bias. the output and feedback polarity are programm able to accommodate either a npn or an pnp transistor to drive a common-anode or common-cathode laser diode. 23 vmod? analog input. inverting terminal of vmod buffer op-amp. connect to v mod + (gain = 1) or feedback resistors network to set a different gain 24 vmod+ analog output. buffered dac output to set the modulation current on the laser driver ic. operates with either a 0? v ref or a (v dd ?v ref ) ? v dd output swing so as to generate either a ground-referenced or a v dd referenced programmed voltage. a simple external circuit can be used to generate a programmable current for those drivers that require a current rather than a voltage input. see ?applicat ions information? section for more details.
micrel, inc. MIC3001 august 2004 9 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 absolute maximum ratings (1) power supply voltage, v dd ................................. +3.8v voltage on clk, data, txfault, vin, rxlos, disable, rsin................................. ?0.3v to +6.0v voltage on any other pin...............?0.3v to v dd +0.3v power dissipation, t a = 85c ............................... 1.5w junction temperature (t j ) .................................. 150c storage temperature (t s ).................. ?65c to +150c esd ratings (3) human body model............................................. 2kv machine mode l .................................................. 300v soldering (2 0sec) .................................................260o c operating ratings (2) power supply voltage, v dda /v ddd ..... +3.0v to +3.6v ambient temperature range (t a ) ... ?40c to +105c package thermal resistance mlf ? ( ja ).............................................. 43c/w electrical characteristics for typical values, t a = 25c, v dda = v ddd = +3.3v, unless otherwise noted. bold values are guaranteed for +3.0v (v dda = v ddd ) 3.6v, t (min) t a t (max) (8) symbol parameter condition min typ max units power supply clk = data = v ddd = v dda ; txdisable low; all da cs at full-scale; all a/d inputs at full-scale; all other pins open. 2.3 3.5 ma i dd supply current clk = data = v ddd = v dda ; txdisable high; fltdac at full-scale; all a/d inputs at full-scale; all other pins open. 2.3 3.5 ma v por power-on reset voltage all registers reset to default values; a/d conversions initiated. 2.9 2.98 v v uvlo under-voltage lockout threshold note 5 2.5 2.73 v v hyst power-on reset hysteresis voltage 170 mv t por power-on reset time v dd > v por (4) 50 s v ref reference voltage 1.210 1.225 1.24 0 v ? v ref / ? v dda voltage reference line regulation 1.7 mv/v temperature-to-digital converter characteristics local temperature measurement error ?40c t a +105c (6) 1 3 c remote temperature measurement error ?40c t a +105c (6) 1 3 c t conv conversion time note 4 60 ms t sample sample period 100 ms remote temperature input, xpn xpn at high level, clamped to 0.6v. 192 400 a i f current to external diode (4) xpn at low level, clamped to 0.6v. 7 12 a
micrel, inc. MIC3001 august 2004 10 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 voltage-to-digital converter characteristics (v rx , v aux , v bias , v mpd , v ild ) symbol parameter condition min typ max units voltage measurement error ?40c t a +105c (6) 1 2.0 %fs t conv conversion time note 4 10 ms t sample sample period note 4 100 ms voltage input, v in (pin 14 used as an adc input) v in input voltage range ?0.3 v dd 3.6v gnda 5.5 v i leak input current v in = v dd or gnd; v aux = v in 55 a c in nput capacitance 10 pf digital-to-voltage converter characteristics (v mod , v bias ) accuracy ?40c t a +105c (6) 1 2.0 %fs t conv conversion time note 4 20 ms dnl differential non-linearity error note 4 0.5 1 lsb bias current sense inputs, v ild +, v ild ? v ild differential input signal range, | v ild + ? v ild ? | 0 v ref /4 mv i in+ v ild + input current 1 a v ild ? referred to v dda +150 a i in? v ild ? input current | v ild + ? v ild ? | = 0.3v v ild ? referred to gnd -150 a c in input capacitance 10 pf apc op amp, fb, v bias , comp gbw gain bandwidth product c comp = 20pf; gain = 1 1 mhz tc vos input offset voltage temperature coefficient (4) 1 v/c i out = 10ma, srce bit = 1 gnda 1.25 v v out output voltage swing i out = -10ma, srce bit = 0 v dda -1.25 v dda v i sc output short-circuit current 55 ma t sc short circuit withstand time t j 150c (4) sec c comp = 20pf; gain = 1, to gnd 55 db psrr power supply rejection ratio c comp = 20pf; gain = 1, to v dd 40 a min minimum stable gain c comp = 20pf, note 4 1 v/v ? v/ ? t slew rate c comp = 20pf; gain = 1 3 v/s ? rfb internal feedback resistor tolerance 20 % ? rfb/ ? t internal feedback resistor temperature coefficient 25 ppm/c start = 01 h 0.375 ma start = 02 h 0.750 ma start = 04 h 1.500 ma i start laser start-up current magnitude start = 08 h 3.000 ma c in pin capacitance 10 pf
micrel, inc. MIC3001 august 2004 11 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 electrical characteristics symbol parameter condition min typ max units v mod buffer op-amp, v mod +, v mod ? gbw gain bandwidth c comp = 20pf; gain = 1 1 mhz tc vos input offset voltage temperature coefficient 1 v/c i bias v mod ? input current 0.1 1 a v out output voltage swing i out = 1ma gnda+75 v dda -75 mv i sc output short-circuit current 35 ma t sc short circuit withstand time t j 150c (4) sec psrr power supply rejection ratio c comp = 20pf; gain = 1, to gnd 65 db c comp = 20pf; gain = 1, to v dd 44 db a min minimum stable gain c comp = 20pf 1 v/v ? v/ ? t slew rate c comp = 20pf; gain = 1 1 v/s c in pin capacitance 10 pf control and status i/o, txdisable, txfault, rsin, rsout(gpo), shdn(txfin), rxlos, /int v il low input voltage 0.8 v v ih high input voltage 2.0 v v ol low output voltage i ol 3ma 0.3 v v oh high output voltage (applies to shdn only) i oh 3ma v ddd ?0.3 v i leak input current 1 a c in input capacitance 10 pf transmit optical power input, v mpd v in input voltage range note 4 gnda v dda v v rx input signal range biasref=0 v ref v biasref=1 v dda ?v ref v dda v c in input capacitance note 4 10 pf i leak input current 1 a received optical power input, vrx, rxpot input voltage range note 4 gnda v dda v v rx valid input signal range (adc input range) 0 v ref v r rxpot(32) end-to-end resistance rxpot = 1f h 32 k ? ? rxpot resistor tolerance 20 % ? rxpot/ ? t resistor temperature coefficient 25 ppm/c ? v rx /v rxpot divider ratio accuracy 00 rxpot 1f h -5 +5 % i leak input current rxpot = 0 (disconnected) 1 a c in input capacitance note 4 10 pf i leak input current 1 a
micrel, inc. MIC3001 august 2004 12 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 electrical characteristics symbol parameter condition min typ max units control and status i/o timing, txfault, txdisable, rsin, rsout, and rxlos t off txdisable assert time from input asserted to optical output at 10% of nominal, c comp = 10nf. 10 s t on txdisable de-assert time from input de-asserted to optical output at 90% of nominal, c comp = 10nf. 1 ms t init initialization time from power on or transmitter enabled to optical output at 90% of nominal and tx_fault de-asserted. (4) 300 ms t init2 power-on initialization time from power on to apc loop enabled. 200 ms t fault txfault assert time from fault condition to txfault assertion. (4) 95 s t reset fault reset time length of time txdisable must be asserted to reset fault condition. 10 s t loss_on rxlos assert time from loss of signal to rxlos asserted. 95 s t loss_off rxlos de-assert time from signal acquisition to los de- asserted. 100 s t data analog parameter data ready from power on to valid analog parameter data available. (4) 400 ms t prop_in txfault, txdisable, rxlos, rsin input propagation time time from input change to corresponding internal register bit set or cleared. (4) 1 s t prop_out txfault, rsout, /int output propagation time from an internal register bit set or cleared to corresponding output change. (4) 1 s fault comparators flttmr fault suppression timer clock period note 4 0.475 0.5 0.525 ms accuracy -3 +3 %/f.s. t reject glitch rejection maximum length pulse that will not cause output to change state. (4) 4.5 s high level 95 %vdda v sat saturation detection threshold low level 5 %vdda power-on hour meter timebase accuracy 0c t a +70c (4) +5 -5 % ?40c t a +105c +10 -10 % resolution note 4 10 hours non-volatile (flash) memory t wr write cycle time(7) from stop of a one to four-byte write transaction.(4) 13 ms data retention 100 years endurance minimum permitted number write cycles 10,000 cycles
micrel, inc. MIC3001 august 2004 13 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 serial data i/o pin, data symbol parameter condition min typ max units i ol = 3ma 0.4 v v ol low output voltage i ol = 6ma 0.6 v v il low input voltage 0.8 v v ih high input voltage 2.1 v i leak input current 1 a c in input capacitance note 4 10 pf serial clock input, clk v il low input voltage 2.7v v dd 3.6v 0.8 v v ih high input voltage 2.7v v dd 3.6v 2.1 v i leak input current 1 a c in input capacitance note 4 10 pf serial interface timing (4) t 1 clk (clock) period 2.5 s t 2 data in setup time to clk high 100 ns t 3 data out stable after clk low 300 ns t 4 data low setup time to clk low start condition 100 ns t 5 data high hold time after clk high stop condition 100 ns t data data ready time from power on to completion of one set of adc conversions; analog data available via serial interface. 400 ms notes: 1. exceeding the absolute maximum rating may damage the device. 2. the device is not guaranteed to function outside its operating rating. 3. devices are esd sensitive. handling 4. precautions recommended. 5. guaranteed by designing and/or testing of related parameters. not 100% tested in production. 6. the mic3000 will attempt to enter its shutdown state when v dd falls below v uvlo . this operation requires time to complete. if the supply voltage falls too rapidly, the operation may not be completed. 7. does not include quantization error. 8. the MIC3001 will not respond to serial bus transactions during an eeprom write-cycl e. the host will receive a nack during t wr . 9. final test on outgoing product is performed at t a = +25c.
micrel, inc. MIC3001 august 2004 14 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 timing diagram serial interface timing
micrel, inc. MIC3001 august 2004 15 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 address map address(s) field size (bytes) name description 0 ?95 96 serial id defined by sep msa g-p nvram; r/w under valid oem password. 96 ? 127 32 vendor specific vendor specific eeprom 128 ? 255 128 reserved reserved for future use. g-p nvram; r/w under valid oem password. table 1. MIC3001 address map, serial address = a0 h address(s) hex dec field size (bytes) name description 00-27 0-39 40 alarm and warning threshold high/low limits for warning and alarms; writeable using oem p/w; read-only otherwise. 28-37 40-55 16 reserved reserved ? do not write; reads undefined. 38-5b 56-91 36 calibration constants numerical constants for external calibration; writeable using oem p/w; read-only otherwise. 5c-5e 92-94 3 reserved reserved ? do not write; reads undefined. 5f 95 1 checksum g-p nvram; writeable us ing oem p/w; ready only otherwise. 60-69 96-105 10 analog data real time analog parameter data. 6a-6d 106-109 4 reserved reserved ? do not write; reads undefined. 6e 110 1 control/status bits control and status bits. 6f 111 1 reserved reserved ? do not write; reads undefined. 70-71 112-113 2 alarm flags alar m status bits; read only. 72-73 114-115 2 reserved reserved ? do not write; reads undefined. 74-75 116-117 2 warning flags warn ing status bits; read only. 76-77 118-119 2 reserved reserved ? do not write; reads undefined. 78-7b 120-123 4 oempw oem password entry field. 7c-7f 124-127 4 vendor specific vendor specif ic. reserved ? do not write; reads undefined. 80-f7 128-247 120 user scratchpad user writeable eeprom. g-p nvram; r/w using any valid password. f8-f9 248-249 2 reserved reserved ? do not write; reads undefined. fa 250 1 usrpwset user password setting; read/write using any p/w; returns zero otherwise. fb 251 1 usrpw entry field for user password. fc-fd 252-253 2 poh power-on hour meter result; ready only. fe 254 1 data ready flags data ready bits for each measured parameter; read only. ff 255 1 user control end-user control and status bits. table 2. MIC3001 address map, serial address = a2 h address(s) hex dec field size (bytes) name description 00-3f 0-63 64 apclutn a.p.c tem perature compensation l.u.t. 40-7f 64-127 64 modlutn vmod te mperature compensation l.u.t. 80-bf 128-191 64 ifltut bias current fault th reshold temperature compensation l.u.t. c0-ff 192-255 64 eollutn bias current high alarm threshold temperature compensation l.u.t. table 3. temperature compensati on tables, serial address = a4 h
micrel, inc. MIC3001 august 2004 16 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 address(s) hex dec field size (bytes) name description 00 0 40 oemcfg0 control/status bits 01 1 16 oemcfg1 control/status bits 02 2 36 oemcfg2 control/status bits 03 3 3 apcset0 apc setpoint 0 04 4 1 apcset1 apc setpoint 1 05 5 10 apcset2 apc setpoint 2 06 6 4 modset nominal modulation dac setpoint 07 7 1 ibflt bias current fault-comparator threshold 08 8 1 txpflt tx power fault threshold 09 9 2 losflt rx los fault-comparator threshold 0a 10 2 flttmr fault comparator masking interval timer setting 0b 11 2 fltmsk fault source mask bits 0c-0f 12-15 2 oempwset password for access to oem areas 10 16 4 oemcal0 oem calibration register 0 11 17 4 oemcal1 oem calibration register 1 12 18 120 lutindx look-up table index read-back 13 19 2 reserved reserved ? do not write; reads undefined. 14 20 1 apcdac reads back current apc dac setting 15 21 1 moddac reads back current modulation dac setting 16 22 2 oemread reads back oem calibration data 17 23 1 losfltn los de-assert threshold 18 24 1 rxpot rxpot tap selection 19 25 1 oemcfg4 i start selection bits 1a-1f 26-31 6 reserved reserved ? do not write; reads undefined. 20-27 32-39 8 pohdata power-on hour meter scratchpad 28-47 40-71 32 rxlut rx power calibration look-up table 48-49 72-73 2 reserved reserved ? do not write; reads undefined. 4a-57 74-87 18 cal internal calibration slope/offset data 59-7d 88-125 37 reserved reserved ? do not write; reads undefined. 7e-fd 126-253 128 scratch oem scratchpad area fe 254 1 mfg_id manufacturer identification (micrel = 42) ff 255 1 dev_id device and die revision table 4. oem configuration registers, serial address = a6 h
micrel, inc. MIC3001 august 2004 17 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 block diagram figure 1. MIC3001 block diagram mic3000 capability in general, the MIC3001 is completely hardware and software backward compatible with the mic3000. every feature available in the mic3000 is still present in the MIC3001. new features have, of course, been added. the following differences between the mic3000 and MIC3001 would be evident to host software: 1. faults do not set alarm or warning bits as in the mic3000. 2. rxopi at register address 69 h at serial address x2 h now contains four bits of data rather then being fixed at zero as in the mic3000. analog-to-digital converter/signal monitoring a block diagram of the monito ring circuit is shown below. each of the five analog parameters monitored by the MIC3001 are sampled in sequence. all five parameters are sampled and the results updated within the t conv internal given in the ?electrical characteristics? section. in oem, mode, the channel that is normally used to measure v in may be assigned to measure the level of the v dda pin or one of five other nodes. this provides a kind of analog loopback for debug and test purposes. the v aux bits in oemcfg0 control which voltage source is being sampled. the various v aux channels are level-shifted differently depending on the signal source, resulting in different lsb values and signal ranges. see table 5.
micrel, inc. MIC3001 august 2004 18 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 figure 2. analog-to-digital converter block diagram channel adc resolution (bits) conditions input range (v) lsb (1) temp 8 n/a 1c vaux 8 see table 6 gain = 0; biasref = 0 gnda - v ref gain = 0; biasref = 1 v dda ? (v dda ? v ref ) 4.77mv gain = 1; biasref = 0 gnda - v ref /4 vmpd 8 gain = 1; biasref = 1 v dda ? (v dda ? v ref /4 ) 1.17mv vild- = vdda v dda ? (v dda ? v ref ) vild 8 vild- = gnda gnda - v ref 4.77mv vrx 12 rxpot = 00 0 - v ref 0.298mv table 5. a/d input signal ranges and resolutions note: 1. assumes typical vref value of 1.22v. channel vaux [2:0] input range (v) lsb (1) (mv) v in 000 = 00 h 0.5v to 5.5v 25.6mv v dda 0001 = 01 h 0.5v to 5.5v 25.6mv v bias 010 = 02 h 0.5v to 5.5v 25.6mv v mod 011 = 03 h 0.5v to 5.5v 25.6mv apcdac 100 = 04 h 0v to v ref 4.77mv moddac 101 = 05 h 0v to v ref 4.77mv fltdac 110 = 06 h 0v to v ref 4.77mv table 6. v aux input signal ranges and resolutions note: 1. assumes typical v ref value of 1.22v.
micrel, inc. MIC3001 august 2004 19 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 internal/external calibration the default mode of calibration in the MIC3001 is external calibration, for which intcal bit (bit 0 in oemcf3 register) is set to 0. this mode is backward compatible with mic3000. the internal calibration mode is selected by setting intcal bit to 1. a/ external calibration the voltage and temperature values returned by the MIC3001?s a/d converter are internally calibrated. the binary values of temph:templ and volth:voltl are in the format called for by sff-8472 under internal calibration. sff-8472 calls for a set of calibration constants to be stored by the transceiver oem at specific non-volatile memory locations, refer to sff-8472 specifications for memory map of calibration coefficient. the MIC3001 provides the non-volatile memory required for the storage of these constants. the digital diagnostic monitoring interface specification should be consulted for full details. slopes and offsets are stored for use with voltage, temperature, bias current, and transmitted power measurements. coefficients for a fourth-order polynomial are provided for use with received power measurements. the host system can retrieve these constants and use them to process the measured data. since voltage and temperature require no calibration, the corresponding slopes should generally be set to unity and the offsets to zero. voltage the voltage values returned by the MIC3001?s a/d converter are internally calibrated. the binary values of volth:voltl are in the format called for by sff-8472 under internal calibration. since vinh:vinl requires no processing, the corresponding slope should be set to unity and the offset to zero. temperature the temperature values returned by the MIC3001?s a/d converter are internally calibrated. the binary values of temph:templ are in the format called for by sff-8472 under internal calibration. since temph:templ requires no processing, the corresponding slope should be set to unity and the offset to zero. bias current bias current is sensed via an external sense resistor as a voltage appearing at vild+ and vild-. the value returned by the a/d is therefore a voltage analogous to bias current. bias current, ibias, is simply vvild/r sense . the binary value in ibiash (ibiasl is always zero) is related to bias current by: (1) the value of the least significant bit (lsb) of ibiash is given by: (2) per sff-8472, the value of the bias current lsb is 2a. the conversion factor, ?slope?, needed is therefore: the tolerance of the sense resistor directly impacts the accuracy of the bias current measurement. it is recommended that the sense resistor chosen be 1% accurate or better. the offset correction, if needed, can be determined by shutting down the laser, i.e., asserting txdisable, and measuring the bias current. any non- zero result gives the offset required. the offset will be equal and opposite to the result of the ?zero current? measurement. tx power transmit power is sensed via an external sense resistor as a voltage appearing at vmpd. it is assumed that this voltage is generated by a sense resistor carrying the monitor photodiode current. in most applications, the signal at vmpd will be feedback voltage on fb. the vmpd voltage may be measured relative to gnd or v dda depending on the setting of the biasref bit in oemcfg1. the value returned by the a/d is therefore a voltage analogous to transmit power. the binary value in txoph (txopl is always zero) is related to transmit power by: (3) for a given implementation, the value of rsense is known. it is either the value of the external resistor or the chosen value of rfb used in the application. the constant, k, will likely have to be determined through experimentation or closed-loop calibration, as it depends on the monitoring photodiode responsivity and coupling efficiency. it should be noted that the apc circuit acts to hold the transmitted power constant. the value of transmit power reported by the circuit should only vary by a small amount as long as apc is functioning correctly.
micrel, inc. MIC3001 august 2004 20 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 rx power received power is sensed as a voltage appearing at vrx. it is assumed that this voltage is generated by a sense resistor carrying the receiver photodiode current. the value returned by the a/d is therefore a voltage analogous to received power. the binary value in rxoph (rxopl is always zero) is related to received power by: (4) for a given implementation, the constant, k, will likely have to be determined through experimentation or closed- loop calibration, as it depends on the gain and efficiencies of the components upstream. in sff-8472 implementations, the external calibration constants can describe up to a fourth-order polynomial in case k is nonlinear. b/ internal calibration if the intcal bit in oemcfg3 is set to 1 (internal calibration selected), the MIC3001 will process each piece of data coming out of the a/d converter before storing the result in memory. linear slope/offset correction will be applied on a per-channel basis to the measured values for voltage, bias current, tx power, and rx power. only offset correction is applied to temperature. the user must store the appropriate slope/offset parameters in memory at the time of transceiver calibration. in the case of rx power, a look-up table is provided that implements eight-segment piecewise-linear correction. this correction may be performed as temperature compensation or as simple slope/offset correction. if static slope/offset correction for rx power is desired, the eight coefficient sets can simply be made the same. the memory maps for these coefficients are shown in table 8 and table 9. the slopes allow for the correction of gain errors. each slope coefficient is an unsigned, sixteen-bit, fixed-point binary number in the format: [mmmmmmmm.llllllll], where m is a data bit (5) in the most-significant byte and l is a data bit in the least significant byte slopes are always positive. the binary point is in between the two bytes, i.e., between bits 7 and 8. this provides a numerical range of 1/256 (0.00391) to 255 in steps of 1/256. the most significant byte is always stored in memory at the lower numerical address. the offsets correct for constant errors in the measured data. each offset is a signed, sixteen-bit, fixed-point binary number. the bit-weights of the offsets are the same as that of the final results. in the case of temperature, the offset?s least significant byte (lsb) is always zero since the MIC3001 does not deal with fractional temperature values. the sixteen bit offsets provide a numerical range of ?32768 to +32767 for voltage, bias current, transmit power, and receive power. the numerical range for the temperature offset is ?32513 (?128) to +32512 (+127) in increments of 256 (1). the format for offsets is: [smmmmmmmllllllll], where s is the sign bit (6) (1 = positive, 0 = negative), m is a data bit in the most-significant byte and l is a data bit in the least significant byte the most significant byte is always stored in memory at the lower numerical address. calibration of voltage, bias current, and tx power are performed using the following calculation: resultn = adc_resultn x slopen + (7) offsetn calibration of temperature is performed using the following calculation: result = adc_result + offset (8) calibration of rx power is performed using the following calculation: result = adc_result x slope(m) + (9) offset(m) where m is the appropriate value from the rx power calibration look-up table. the results of these calculations are rounded to sixteen bits in length. if the seventeenth most significant bit is a one, the result is rounded up to the next higher value. if the seventeenth most significant bit is zero, the upper sixteen bits remain unchanged. the bit-weights of the offsets are the same as that of the final results. for sff-8472 compatible applications, these bit-weights are given in table 7. parameter magnitude of lsb temperature 1.0c (1) voltage 100v bias current 2a tx power 0.1w rx power 0.1w table 7. lsb values of offset coefficients note: 1. the lsbytes of the temperature is always zero.
micrel, inc. MIC3001 august 2004 21 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 address(s) hex dec field size name description 48-49 72-73 2 reserved reserved. (there is no slope for temperature.) do not write; reads undefined. 4a-4b 74-75 2 toffh:toffl temperature offset; signed fixed point; lsb is always zero; msb is at lower physical address. 4c-4d 76-77 2 vslph:vslpl voltage slope; unsigned fixed-point; msb is at lower physical address. 4e-4f 78-79 2 voffh:voffl voltage offset; signed fixed point; msb is at lower physical address. 50-61 80-81 2 islph:islpl bias current slope; unsign ed fixed-point; msb is at lower physical address. 52-63 82-83 2 ioffh:ioffl bias current offset; sign ed fixed point; msb is at lower physical address. 54-65 84-85 2 txslph: txslpl tx power slope; unsigned fixed-point; msb is at lower physical address. 56-67 86-87 2 txoffh: txoffl tx power offset; signed fixed point; msb is at lower physical address. table 8. internal calibration coefficient memory map ? part i address(s) hex dec field size name description 28-29 40-41 2 rxslp0h: rxslp0l rx power slope 0; unsigned fixed-point; msb is at lower physical address. 2a-2b 42-43 2 rxoff0h: rxoff0l rx power offset 0; signed twos-complement; msb is at lower physical address. 2c-2d 44-45 2 rxslp1h: rxslp1l rx power slope 1; unsigned fixed-point; msb is at lower physical address. 2e-2f 46-47 2 rxoff1h: rxoff1l rx power offset 1; signed twos-complement; msb is at lower physical address. 30-31 48-49 2 rxslp2h: rxslp2l rx power slope 2; unsigned fixed-point; msb is at lower physical address. 32-33 50-51 2 rxoff2h: rxoff2l rx power offset 2; signed twos-complement; msb is at lower physical address. 34-35 52-53 2 rxslp3h: rxslp3l rx power slope 3; unsigned fixed-point; msb is at lower physical address. 36-37 54-55 2 rxoff3h: rxoff3l rx power offset 3; signed twos-complement; msb is at lower physical address. 38-39 56-57 2 rxslp4h: rxslp4l rx power slope 4; unsigned fixed-point; msb is at lower physical address. 3a-3b 58-59 2 rxoff4h: rxoff4l rx power offset 4; signed twos-complement; msb is at lower physical address. 3c-3d 60-61 2 rxslp5h: rxslp5l rx power slope 5; unsigned fixed-point; msb is at lower physical address. 3e-3f 62-63 2 rxoff5h: rxoff5l rx power offset 5; signed twos-complement; msb is at lower physical address. 40-41 64-65 2 rxslp6h: rxslp6l rx power slope 6; unsigned fixed-point; msb is at lower physical address. 42-43 66-67 2 rxoff6h: rxoff6l rx power offset 6; signed twos-complement; msb is at lower physical address. 44-45 68-69 2 rxoff7h: rxoff7l rx power slope 7; signed twos-complement; msb is at lower physical address. 46-47 70-71 2 rxslp7h: rxslp7l rx power slope 7; signed fixed-point; msb is at lower physical address. table 9. internal calibration coefficient memory map ? part ii
micrel, inc. MIC3001 august 2004 22 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 c/ adc result registers reading in the present revision of MIC3001, the adc result registers should be read as 16 bit registers under internal calibration while under external calibration they should be read as 8 bit registers at the msb address. for example, tx power should be read under internal calibration as 16 bits at address a2 h : 66?67 and under external calibration as 8 bits at address a2 h : 66 h . rxpot a programmable, non-volatile digitally controlled potentiometer is provided for adjusting the gain of the receive power measurement signal chain in the analog domain. five bits in the rxpot register are used to set and adjust the position of potentiometer. rxpot functions as a programmable divider or attenuator. it is adjustable in steps from 1:1 (no divider action) down to 1/32 in steps of 1/32. if rxpot is set to zero, the divider is bypassed completely. there will be no scaling of the input signal, and the resistor network will be disconnected from the vrx pin. at all other settings of rxpot, there will be a 32k ? (typical) load seen on vrx. figure 3. rxpot block diagram laser diode bias control the MIC3001 can be configured to generate a constant bias current using electrical feedback, or regulate average transmitted optical power using a feedback signal from a monitor photodiode, see figure 4. an operational amplifier is used to control laser bias current via the v bias output. the vbias pin can drive a maximum of 10ma. an external bipolar transistor provides current gain. the polarity of the op amp?s output is programmable biasref in oemcfg1 in order to accommodate either npn or pnp transistors that drive common anode and common cathode laser, respectively. additionally, the polarity of the feedback signal is programmable for use with either common-emitter or emitter-follower transistor circuits. furthermore, the reference level for the apc circuit is selectable to accommodate electrical, i.e., current feedback, or optical feedback via a monitor photodiode. finally, any one of seven different internal feedback resistors can be selected. this internal resistor can be used alone or in parallel with an external resistor. this wide range of adjustability (50:1) accommodates a wide range of photodiode current, i.e, wide range of transmitter output power. the apc operating point can be kept near the mid- scale value of the apc dac, insuring maximum snr, maximum effective resolution for digital diagnostics, and the widest possible dac adjustment range for temperature compensation, etc. see figure 5. the apccal bit in oemcal0 is used to turn the apc function on and off. it will be turned off in the MIC3001?s default state as shipped from the factory. when apc is on, the value in the selected apcsetx register is added to the signed value taken from the apc look-up table and loaded into the v bias dac. when apc is off, the v bias dac may be written directly via the v bias register, bypassing the look- up table entirely. this provides direct control of the laser diode bias during setup and calibration. in either case, the v bias dac setting is reported in the apcdac register. the apccfg bits determine the dacs response to higher or lower numeric values. figure 4. MIC3001 apc and modulation control block diagram figure 5. programmable feedback resistor
micrel, inc. MIC3001 august 2004 23 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 laser modulation control as shown in figure 4, a temperature-compensated dac is provided to set and control the laser modulation current via an external laser driver circuit. modref in oemcfg0 selects whether the v mod dac output swings up from ground or down from v dd . if the laser driver requires a voltage input to set the modulation current, the MIC3001?s v mod output can drive it directly. if a current input is required, a fixed resistor can be used between the driver and the v mod output. several different configurations are possible as shown in figure 7. when apc is on, i.e., the apccal bit in oemcal0 is set to 0, the value corresponding to the current temperature is taken from the modlut look-up table, added to modset, and loaded into the v mod dac. when apc is off, the value in v mod is loaded directly into the v mod dac, bypassing the look-up table entirely. this provides for direct modulation control for setup and calibration. the modref bit determines the dacs response to higher or lower numeric values. figure 6. transmitter configurations supported by MIC3001 figure 7. v mod configured as voltage output with gain
micrel, inc. MIC3001 august 2004 24 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 power on and laser start-up when power is applied, t he MIC3001 initializes its internal registers and state machine. this process takes t por , about 50ms. following t por , analog-to-digital conversions begin, serial communication is possible, and the por bit and data ready bits may be polled. the first set of analog data will be available t conv after t por . MIC3001s are shipped from the factory with the output enable bit, oe, set to zero , off. the MIC3001?s power-up default state, therefore, is apc off, v bias , v mod , and shdn outputs disabled. v bias , v mod , and shdn will be floating (high impedance) and the laser diode, if connected, will be off. once th e device is incorporated into a transceiver and properly configured, the shutdown states of shdn, v bias and v mod will be determined by the state of the apc configuration and oe bits. table 10, table 11, and table 12 illustrate the shutdown states of the various laser control outputs versus the control bits. configuration bits shutdown state oe spol shdn 0 don?t care hi-z 1 0 gnd 1 1 v dd table 10. shutdown state of shdn vs. configuration bits configuration bits v bias shutdown state oe inv biasref v bias 0 don?t care don?t care hi-z 1 don?t care 0 gnd 1 don?t care 1 v dd table 11. shutdown state of v bias vs. configuration bits configuration bits v mod shutdown state oe modref v mod 0 don?t care hi-z 1 0 gnd 1 1 v dd table 12. shutdown state of v mod vs. configuration bits in order to facilitate hot-plugging, the laser diode is not turned on until t init2 after power-on. following t init2 , and assuming txdisable is not asserted, the dacs will be loaded with their initial values. since t conv is much less than t init2 , the first set of analog data, including temperature, is available at t init2 . temperature compensation will be applied to the dac values if enabled. apc will begin if oe is asserted. (if the output enable bit, oe, is not set, the v mod , v bias , and shdn outputs will float indefinitely.) figure 8 shows the power- up timing of the MIC3001. if txdisable is asserted at power-up, the v mod and v bias outputs will stay in their shutdown states following MIC3001 initialization. a/d conversions will be gin, but the laser will remain off.
micrel, inc. MIC3001 august 2004 25 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 figure 8. MIC3001 power-on timing (oe = 1) fault comparators in addition to detecting and reporting the events specified in sff-8472, the MIC3001 also monitors five fault conditions: inadequate supply voltage, thermal diode faults, excessive bias current, excessive transmit power, and apc op-amp saturation. comparators monitor these parameters in order to respond quickly to fault conditions that could indicate link failure or safety issues, see figure 9. when a fault is detected, the laser is shut down and txfault is asserted. each fault source may be independently disabled using the fltmsk register. fltmsk is non-volatile, allowing faults to be masked only during calibration and testing or permanently. figure 9. fault comparator logic thermal diode faults are detected within the temperature measurement subsystem when an out-of-range signal is detected. a window comparator circuit monitors the voltage on the compensation capacitor to detect apc op-amp saturation (figure 10). op-amp saturation indicates that some fault has occurred in the control loop such as loss of feedback. the saturation detector is blanked for a time, tflttmr, following laser turn-on since the compensation voltage will essentially be zero at turn-on. the flttmr interval is programmable from 0.5ms to 127ms (typical) in increments of 0.5ms (fflttmr). note that a saturation comparator cannot be relied upon to meet certain eye- safety standards that require 100ms response times. this is because the operation of a saturation detector is limited by the loop bandwidth, i.e., the choice of c comp . even if the comparator itself was very fast, it would be subject to the limited slew-rate of the apc op-amp. only the other fault comparator channels will meet <100ms timing requirements. the MIC3001 can also except and respond to fault inputs from external devices. see ?shdn and txfin? section. a similar comparator circuit monitors received signal strength and asserts rxlos when loss-of-signal is detected (figure 11). rxlos will be asserted when and if vrx drops below the level programmed in losflt. hysteresis is implemented such that rxlos will be de- asserted when vrx subsequently rises above the level programmed in losfltn. the loss-of-signal comparator may be disabled completely by setting the losdis bit in oemcfg3. once the los comparator is disabled, an external device may drive rxlos. the state of the rxlos pin is reported in the cntrl register regardless of whether it is driven by the internal comparator or by an external device. a programmable digital-to-analog converter provides the comparator reference voltages for monitoring received signal strength, transmit power, and bias current. glitches less than 10ms (typical) in length are rejected by
micrel, inc. MIC3001 august 2004 26 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 the fault comparators. since laser bias current varies greatly with temperature, there is a temperature compensation look-up table for the bias current fault dac value. when a fault condition is detected, the laser will be immediately shutdown and txfault will be asserted. the v mod , v bias , and shdn (if enabled) outputs will be driven to their shutdown state according to the state of the configuration bits. the shutdown states of v mod , v bias , and shdn versus the configuration bit settings are shown in table 10, table 11, and table 12. shdn and txfin shdn and txfin are optional functions of pin 7. shdn is an output function and is designed to drive a redundant safety switch in the laser current path. txfin is an input function and serves as an input for fault signals from external devices that must be reported to the host via txfault. the shdn function is designed for applications in which the MIC3001 is performing all apc and laser management tasks. the txfin function is for situations in which an external device such as a laser diode driver ic is performing laser management tasks, including fault detection. if the txfin bit in oemcfg3 is zero (the default mode), shdn will be activated anytime the laser is supposed to be off. thus, it will be active if 1) txdisable is asserted, 2) stxdis in cntrl, is set, or 3) a fault is detected. shdn is a push-pull logic output. its polarity is programmable via the spol bit in oemcfg1. if txfin is set to one, pin 7 serves as an input that accepts fault signals from external devices such as laser diode driver ics. multiple txfault signals cannot simply be wire-ored together as they are open-drain and active high. the input polarity is programmable via the txfpol bit in oemcfg3. txfin is logically ored with the MIC3001?s internal fault sources to produce txfault and determine the value of the transmit fault bit in cntrl. see figure 9. figure 10. saturation detector figure 11. rxlos comparator logic temperature measurement the temperature-to-digital converter for both internal and external temperature data is built around a switched current source and an eight-bit analog-to-digital converter. the temperature is calculated by measuring the forward voltage of a diode junction at two different bias current levels. an internal multiplexer directs the current source?s output to either an internal or external diode junction. the value of the zone bit in oemcfg1 determines whether readings are taken from the on-chip sensor or from the xpn input. the external pn junction may be embedded in an integrated circuit, or it may be a diode-connected discrete transistor. this data is also used as the input to the temperature compensation look-up tables. each time temperature is sampled and an updated value acquired, new corrective values for imod and the apc setpoint are read from the corresponding tables, added to the set values, and transferred to dacs. diode faults the MIC3001 is designed to respond in a failsafe manner to hardware faults in the temperature sensing circuitry. if the connection to the sensing diode is lost or the sense line is shorted to v dd or ground, the temperature data reported by the a/d converter will be forced to its full-scale value (+127c). the diode fault flag, dflt, will be set in oemcfg1, txfault will be asserted, and the high temperature alarm and warning flags will be set. the reported temperature will remain +127c until the fault condition is cleared. diode faults may be reset by toggling txdisable, as with any other fa ult. diode faults will not be detected at power up until the first a/d conversion cycle is completed. diode faults are not reported while txdisable is asserted. temperature compensation since the performance characteristics of laser diodes and photodiodes change with operating temperature, the MIC3001 provides a facility for temperature compensation of the a.p.c. loop setpoint, laser modulation current, bias current fault comparator threshold, and bias current high alarm flag threshold. temperature compensation is
micrel, inc. MIC3001 august 2004 27 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 performed using a look-up table (lut) that stores values corresponding to each measured temperature over a 128c span. four identical tables reside at serial address a4h as summarized in table 13. the range of temperatures spanned by the tables is programmable via the lutoff register. each table entry is a signed twos complement number that is used as an offset to the parameter being compensated. the default value of all table entries is zero, gi ving a flat response. the a/d converter reports a new temperature sample each t conv . this occurs at roughly 10hz. to prevent temperature oscillation due to thermal or electrical noise, sixteen successive temperature samples are averaged together and used to index the luts. temperature compensation results are therefore updated at 16xt conv intervals, or about 1.6 seconds. this can be expressed as shown in equation10. (10) each time an updated average value is acquired, a new offset value for the apc setpoint is read from the corresponding look-up table (see table 14) and transferred to the apc circuitry. this is illustrated in equation 11. in a same way, new offset values are taken from similar look-up tables (see table 15 and table 16), added to the nominal values and transferred into the modulation and fault comparator dacs. the bias current high alarm threshold, is compensated using a fourth look- up table (see table 17). this compensation happens internally and does not affect any host-accessible registers. (11) if the measured temperature is greater than the maximum table value, the highest value in each table is used. if the measured temperature is less than the minimum, the minimum value is used. hysteresis is employed to further enhance noise immunity and prevent oscillation about a table threshold. each table entry spans two degrees c. the table index will not change unless the new temperature average results in a table index beyond the midpoint of the next entry in either direction. there is therefore 2 to 3c of hysteresis on temperature compensation changes. the table index will never oscillate due to quantization noise as the hysteresis is much larger than 1 2 lsb. byte addresses function 00h?3fh apc look-up table 40h?7fh i mod look-up table 80h?bfh iflt look-up table c0h?ffh bias high alarm look-up table table 13. temperature comp ensation look-up tables, serial address i2cadr + 4 h
micrel, inc. MIC3001 august 2004 28 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 register address table offset temperature offset (c) 0 00h 0 1 2 01h 1 3 4 02h 2 5 ? ? ? ? ? ? ? ? ? 124 3eh 62 125 126 3fh 63 127 table 14. apc temperature compensation look-up table, serial address 12c adr+4 h register address table offset temperature offset (c) 0 40h 0 1 2 41h 1 3 4 42h 2 5 ? ? ? ? ? ? ? ? ? 124 7eh 62 125 126 7fh 63 127 table 15. v mod temperature compensation look-up table, serial address 12c adr+4 h register address table offset temperature offset (c) 0 80h 0 1 2 81h 1 3 4 82h 2 5 ? ? ? ? ? ? ? ? ? 124 8eh 62 125 126 8fh 63 127 table 16. i bias comparator temperature compensation look-up table, serial address 12c adr+4 h register address table offset temperature offset (c) 0 c0h 0 1 2 c1h 1 3 4 c2h 2 5 ? ? ? ? ? ? ? ? ? 124 feh 62 125 126 ffh 63 127 table 17. bias current high alarm temperature compensation table, serial address 12c adr+4 h
micrel, inc. MIC3001 august 2004 29 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 the lutoff register determines the range of measured temperatures that are actually spanned by the tables. the temperature span of the tables versus the value of lutoff is given in table 18. lutoff temperature span t comp (min) ? t comp (max) 00h 0c to 127c 01h ?2c to 125c 02h ?4c to +123c ? ? ? ? ? ? 0fh ?30c to 97c table 18. range of temperature compensation table vs. lutoff the internal state machine calculates a new table index each time a new average temperature value becomes available. this table index is derived from the average temperature value and lutoff. the table index is then converted into a table address for each of the four look-up tables. these operations can be expressed as: (12) where tavg(n) is the current average temperature; and table_address=index+base_addres where base_address is the physical base address of each table, i.e., 00 h , 40 h , 80 h , or c0 h (all tables reside in the i2cadr+4 page of memory). at any given time, the current table index can be read in the lutindx register. figures 12 and 13 illustrate the operation of the temperature compensation tables. figure 12 is a graphical illustration of the use of the lutoff register to control the temperature range spanned by the temperature compensation tables. note that, if the lutindx becomes greater than 63 or less than zero, the maximum or minimum table value is used, respectively. the tables do not ?roll over.? figure 13 llustrates that the table values are used as offsets to the nominal value of the parameter in question. apcset is used as an example, but all four tables function identically. note that the shape and magnitude of the compensation curve do not change as the nominal value changes. figure 12. examples of lutoff operation
micrel, inc. MIC3001 august 2004 30 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 figure 13. temperature compensation examples
micrel, inc. MIC3001 august 2004 31 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 alarms and warning flags there are twenty different conditions that will cause the MIC3001 to set one of the bits in the warnx or alarmx registers. these conditions are listed in table 19. the less critical of these events generate warning flags by setting a bit in warn0 or warn1. the more critical events cause bits to be set in alarm0 or alarm1. an event occurs when any alarm or warning condition becomes true. each event causes its corresponding status bit in alarm0, al arm1, warn0, or warn1 to be set. this action cannot be masked by the host. the status bit will remain set until the host reads that particular status register, a power on-off cycle occurs, or the host toggles txdisable. if txdisable is asserted at any time during normal operation, a/d conversions continue. the a/d results for all parameters will continue to be reported. all events will be reported in the normal way. if they have not already been individually cleared by read operations, when txdisable is de-asserted, all status registers will be cleared. control and status i/o the logic for the transceiver control and status i/o is shown schematically in figure 14. note that the internal drivers on rxlos, rate_select, and txfault are all open-drain. these signals may be driven either by the internal logic or external drivers connected to the corresponding MIC3001 pins. in any case, the signal level appearing at the pins of the MIC3001 will be reported in the control register status bits. note that the control bits for tx_disable and rate_select and the status bits for txfault and rxlos do not meet the timing requirements specified in the sfp msa or the gbic specification, revision 5.5 (sff- 8053) for the hardware signals. the speed of the serial interface limits the rate at which these functions can be manipulated and/or reported. the response time for the control and status bits is given in the ?electrical characteristics? section. event condition MIC3001 response temperature high alarm temp > tmax set alarm0[7] temperature low alarm temp < tmin set alarm0[6] voltage high alarm vin > vmax set alarm0[5] voltage low alarm vin < vmin set alarm0[4] tx bias high alarm ibias > ibmax set alarm0[3] tx bias low alarm ibias < ibmin set alarm0[2] tx power high alarm txop > txmax set alarm0[1] tx power low alarm txop < txmin set alarm0[0] rx power high alarm rxop > rxmax set alarm1[7] rx power low alarm rxop < rxmin set alarm1[6] temperature high warning temp > thigh set warn0[7] temperature low warning temp < tlow set warn0[6] voltage high warning vin > vhigh set warn0[5] voltage low warning vin < vlow set warn0[4] tx bias high warning ibias > ibhigh set warn0[3] tx bias low warning ibias < iblow set warn0[2] tx power high warning txop > txhigh set warn0[1] tx power low warning txop < txlow set warn0[0] rx power high warning rxop > rxhigh set warn1[7] rx power low warning rx op < rxlow set warn1[6] temperature high alarm temp > tmax set alarm0[7] table 19. MIC3001 events
micrel, inc. MIC3001 august 2004 32 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 figure 14. control and status i/o logic system timing the timing specifications for MIC3001 control and status i/o are given in the ?electrical characteristics? section. figure 15. transmitter on-off timing figure 16. initialization timing with txdisable asserted
micrel, inc. MIC3001 august 2004 33 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 figure 17. initialization timing with txdisable not asserted figure 18. loss-of-signal (los) timing figure 19. transmit fault timing
micrel, inc. MIC3001 august 2004 34 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 figure 20. successfully clearing a fault condition figure 21. unsuccessful attempt to clear a fault
micrel, inc. MIC3001 august 2004 35 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 warm resets the MIC3001 can be reset to its power-on default state during operation by setting the reset bit in oemcfg0. when this bit is set, txfault and rxlos will be de- asserted, all registers will be restored to their normal power-on default values, and any a/d conversion in progress will be halted and th e results discarded. the state of the MIC3001 following this operation is indistinguishable from a power-on reset. power-on hour meter the power-on hour meter logs operating hours using an internal real-time clock and stores the result in nvram. the hour count is incremented at ten-hour intervals in the middle of each interval. the first increment therefore takes place five hours after power-on. time is accumulated whenever the MIC3001 is powered. the hour meter?s timebase is accu rate to 5% over all MIC3001 operating conditions. the counter is capable of storing counts of more than thirty years, but is ultimately limited by the write-cycle endurance of the non-volatile memory. this implies a range of at least twenty years. actual results will depend on the operating conditions and write-cycle endurance of the part in question. two registers, pohh and pohl, contain a 15-bit power-on hour measurement and an error flag, pohflt. great care has been taken to make the MIC3001?s hour meter immune to data corruption and to insure that valid data is maintained across power cycles. the hour meter employs multiple data copies and error correction codes to maintain data validity. this data is stored in the pohdata registers. if pohflt is set, however, the power-on hour meter data has been corrupted and should be ignored. it is recommended that a two-byte (or more) sequential read operation be performed on pohh and pohl to insure coherency between the two registers. these registers are accessible by the oem using a valid oem password. the only operation that should be performed on these registers is to clear the hour meters initial value, if necessary, at the time of product shipment. the hour meter result may be cleared by setting all eight pohdata bytes to 00 h . power-on hour result format high byte, pohh low byte, pohi error flag elapsed time / 10 hours, msbs elapsed time / 10 hours, lsbs msb lsb table 20. power-on hour meter result format test and calibration features numerous features are included in the MIC3001 to facilitate development, testing, and diagnostics. these features are available via registers in the oem area. as shown in table 21, these features include: function description control register(s) analog loop-back provides analog visibility of op- amp and dac outputs via the adc oemcfg0 fault comparator disable control disables the fault comparator oemcal0 fault comparator spin-on-channel mode selects a single fault comparator channel oemcal0 fault comparator output read-back allows host to read individual fault comparator outputs oemrd rsout, /int read-back allows host to read the state of these pins oemrd inhibit eeprom write cycles speeds repetitive wr ites to registers backed up by nvram oemcal0 apc calibration mode allows direct writ es to moddac and apcdac (temperature compensation not used) oemcal0 continuity checking forcing of rxlos, txfault, /int oemcal0 halt a/d stops a/d conversions ; adc in one-shot mode oemcal1 adc idle flag indicates adc status oemcal1 a/d one-shot mode performs a single a/d c onversion on the selected input channel oemcal1 a/d spin-on-channel mode selects a single input channel oemcal1 channel selection selects adc or fault compar ator channel for spin-on-channel modes oemcal1 lut index read-back permits visibility of the lu t index calculated by the state-machine lutindx manufacturer and device id registers facilitates pr esence detection and version control mfg_id, dev_id table 21. test and diagnostic features
micrel, inc. MIC3001 august 2004 36 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 serial port operation the MIC3001 uses standard write_byte, read_byte, and read_word operations for communication with its host. it also supports page_write and sequential_read transactions. the write_byte operation involves sending the device?s slave address (with the r/w bit low to signal a write operation), followed by the address of the register to be operated upon and the data byte. the read_byte operation is a composite write and read operation: the host first sends the device?s slave address followed by the register address, as in a write operation. a new start bit must then be sent to the MIC3001, followed by a repeat of the slave address with the r/w bit (lsb) set to the high (read) state. the data to be read from the part may then be clocked out. a read_word is similar, but two successive data bytes are clocked out rather than one. these protocols are shown in figure 22 to 25. the MIC3001 will respond to up to four sequential slave addresses depending on whether it is in oem or user mode. a match between one of the MIC3001?s addresses and the address specified in the serial bit stream must be made to initiate communication. the MIC3001 responds to slave addresses a0 h and a2 h in user mode; it also responds to a4 h and a6 h in oem mode (assuming i2cadr = ax h ). page writes to increase the speed of multi-byte writes, the MIC3001 allows up to four consecutive bytes (one page) to be written before the internal write cycle begins. the entire non- volatile memory array is organized into four-byte pages. each page begins on a register address boundary where the last two bits of the address are 00 b . thus the page is composed of any four consecutive bytes having the addresses xxxxxx00 b , xxxxxx01 b , xxxxxx10 b , and xxxxxx11 b . the page write sequence begins just like a write_byte operation with the host sending the slave address, r/w bit low, register address, etc. after the first byte is sent the host should receive an acknowledge. up to three more bytes can be sent in sequence. the MIC3001 will acknowledge each one and increment its internal address register in anticipation of the next byte. after the last byte is sent, the host issues a stop. the MIC3001?s internal write process then begins. if more than four bytes are sent, the MIC3001?s internal address counter wraps around to the beginning of the four-byte page. to accelerate calibration and testing, nvram write cycles can be disabled completely by setting the wrinh bit in oemcal0. writes to registers that do not have nvram backup will not incur write-cycle delays when writes are inhibited. write operations on registers that exist only in nvram will still incur write cycle delays. figure 22. write byte protocol figure 23. read byte protocol figure 24. read_word protocol
micrel, inc. MIC3001 august 2004 37 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 figure 25. four-byte page_white protocol acknowledge polling the MIC3001?s non-volatile memory cannot be accessed during the internal write process. to allow for maximum speed bulk writes, the MIC3001 supports acknowledge polling. the MIC3001 will not acknowledge serial bus transactions while internal writes are in progress. the host may therefore monitor for the end of the write process by periodically checking for an acknowledgement. write protection and data security oem password a password is required to access the oem areas of the MIC3001, specifically the non-volatile memory, look-up tables, and registers at serial addresses a4 h and a6 h . a four-byte field, oempwset, at serial address a6 h is used for setting the oem password. the oem password is set by writing oempwset with the new value. the password comparison is performed following the write to the msb of the oempw, address 7b h at serial address a2 h . therefore, this byte must be written last! a four- byte burst-write sequence to address 78 h may be used as this will result in the msb being written last. the new password will not take effect until after a power-on reset occurs or a warm reset is performed using the rst bit in oemcfg0. this allows the new password to be verified before it takes effect. the corresponding four-byte field for password entry, oempw, is located at serial address a2 h . this field is therefore always visible to the host system. oempw is compared to the four-byte oempwset field at serial address a6 h . if the two fields match, access is allowed to the oem areas of the MIC3001 non-volatile memory at serial addresses a4 h and a6 h . if oempwset is all zeroes, no password security will exist. the value in oempw will be ignored. this helps prevent a deliberately unsecured MIC3001 from being inadvertently locked. once a valid password is entered, the MIC3001 oem areas will be accessible. the oem areas may be re- secured by writing an incorrect password value at oempw, e.g., all zeroes. in all cases oempw must be written lsb first through msb last. the oe m areas will be inaccessible following the final write operation to oempw?s lsb. the oempw field is reset to all zeros at power on. any values written to these locations will be readable by the host regardless of the locked/unlocked status of the device. if oempwset is set to zero (00000000 h ), the MIC3001 will remain unlocked regardless of the contents of the oempw field. this is the factory default security setting. note: a valid oem password allows access to the oem and user areas of the chip, i.e., the entire memory map, regardless of any user password that may be in place. once the oem areas are locked, t he user password can provide access and write protection for the user areas. user password a password is required to access the user areas of the MIC3001, specifically the non-volatile memory at serial addresses a0 h and a2 h . a one-byte field, usrpwset at serial address a2 h is used for setting the user password. usrpwset is compared to the usrpw field at serial address a2 h . if the two fields match, access is allowed to the user areas of the MIC3001 non-volatile memory at serial addresses a0 h and a2 h . the user password is set by writing usrpwset with the new value. the new password will not take effect until after a power-on reset occurs or a warm reset is performed using the rst bit in oemcfg0. this allows the new password to be verified before it takes effect. note: a valid oem password allows access to the oem and user areas of the chip, i.e., the entire memory map, regardless of any user password that may be in place. once the oem areas are locked, t he user password can provide access and write protection for the user areas. if a valid oem password is in place, the user password will have no effect.
micrel, inc. MIC3001 august 2004 38 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 detailed register descriptions note: serial bus addresses shown assume that i2cadr = ax h . alarm threshold registers temperature high alarm threshold msb (tmaxh) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0c) serial address a2 h = 1010001 b byte address 00 = 00 h each lsb represents one degree centigrade. this register is to be used in conjunction with tmaxl to yield a sixteen-bit temperature value. the value in this register is uncalibrated. the value in tmaxh is compared against temph. alarm bit ax is set if temph > tmaxh. temperature high alarm threshold lsb (tmaxh) d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0c) serial address a2 h = 1010001 b byte address 01 = 01 h this register is to be used in conjunction with tmaxh to yield a sixteen-bit temperature value. the value in tmaxh is compared against temph. alarm bit ax is set if tmaxh > temph. since templ is always zero, it is recommended that this register always be programmed to zero. this register is prov ided for compliance with sff-8472. it is not used by the MIC3001 when doing threshold comparisons and setting alarm or warning bits. temperature low alarm threshold msb (tminh) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0c) serial address a2 h = 1010001 b byte address 02 = 02 h each lsb represents one degree centigrade. this register is to be used in conjunction with tminl to yield a sixteen-bit temperature value. the value in tminh is compared ag ainst temph. alarm bit ax is set if temph < tminh. temperature low alarm threshold lsb (tminl) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0c) serial address a2 h = 1010001 b byte address 03 = 03 h this register is to be used in conjunction with tminh to yie ld a sixteen-bit temperature value. the value in tminh is compared against temph. alarm bit ax is set if temp h < tminh. since templ is always zero, it is recommended that this register always be programmed to zero. this register is provided for compli ance with sff-8472. it is not used by the MIC3001 when doing threshold comparisons and setting alarm or warning bits.
micrel, inc. MIC3001 august 2004 39 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 voltage high alarm threshold msb(vmaxh) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0v) serial address a2 h = 1010001 b byte address 08 = 08 h each lsb represents 25.6mv. this register is to be used in conj unction with vmaxl to yield a sixteen-bit value. the value in tminh is compared against vinh. alarm bit ax is set if vinh > vmaxh. voltage high alarm threshold lsb(vmaxl) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0v) serial address a2 h = 1010001 b byte address 09 = 09 h each lsb represents 100 v. this register is to be used in conjunction with vinh to yield a sixteen-bit value. the value in vmaxh is compared against vinh. alarm bit ax is set if vinh > vmaxh. since vinl is always zero, it is recommended that this register always be programmed to zero. this register is prov ided for compliance with sff-8472. it is not used by the MIC3001 when doing threshold comparisons and setting alarm or warning bits. voltage low alarm threshold msb (vminh) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0v) serial address a2 h = 1010001 b byte address 10 = 0a h each lsb represents 25.6mv. this register is to be used in conj unction with vminl to yield a sixteen-bit value. the value in th is register is uncalibrated. the value in vminh is com pared against vinh. alarm bit ax is set if vinhMIC3001 when doing threshold comparisons and setting alarm or warning bits.
micrel, inc. MIC3001 august 2004 40 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 bias current high alarm threshold msb (imaxh) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0ma) serial address a2 h = 1010001 b byte address 16 = 10 h this register is to be used in conjunction with imaxl to yiel d a sixteen-bit value. the value in this register is uncalibrated. the value in imaxh is compared against ildh . alarm bit ax is set if ildh > imaxh. bias current high alarm threshold lsb (imaxl) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0ma) serial address a2 h = 1010001 b byte address 17 = 11 h each lsb represents 2 a. this register is to be used in conjunction with imaxh to yield a sixteen-bit value. the value in this register is uncalibrated. the value in imaxh is compared against il dh. alarm bit ax is set if ildh > imaxh. since ildl is alway s zero, it is recommended that this register always be programmed to zero. this register is provided for compliance with sff- 8472. it is not used by the MIC3001 when doing thre shold comparisons and setting alarm or warning bits. bias current low alarm threshold msb (iminh) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0ma) serial address a2 h = 1010001 b byte address 18 = 12 h this register is to be used in conjunction with iminl to yiel d a sixteen-bit value. the value in this register is uncalibrated. the value in iminh is compared against ildh. alarm bit ax is set if ildh < iminh. bias current low alarm threshold lsb (iminl) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0ma) serial address a2 h = 1010001 b byte address 19 = 13 h each lsb represents 2 a. this register is to be used in conjunction with iminh to yield a sixteen-bit value. the value in this register is uncalibrated. the value in iminh is compared against il dh. alarm bit ax is set if ildh < iminh. since ildl is alway s zero, it is recommended that this register always be programmed to zero. this register is provided for compliance with sff- 8472. it is not used by the MIC3001 when doing thre shold comparisons and setting alarm or warning bits.
micrel, inc. MIC3001 august 2004 41 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 tx optical power high alarm msb (txmaxh) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0mw) serial address a2 h = 1010001 b byte address 24 = 18 h each lsb represents 25.6 w. this register is to be used in conjunction wi th txopl to yield a sixteen-bit value. the values in txoph:txopl are in an unsigned binary format. the value in this register is uncalibrated. the value in txmaxh is compared against txoph. alarm bit ax is set if txoph > txmaxh. tx optical power high alarm lsb (txmaxl) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0mw) serial address a2 h = 1010001 b byte address 25 = 19 h each lsb represents 0.1 w. this register is to be used in conjunction with txmaxh to yield a sixteen-bit value. the values in txoph:txopl are in an unsigned binary format. the value in this register is uncalibrated. the value in txmaxh is compared against txoph. alarm bit ax is set if txoph > txmaxh. since tx opl is always zero, it is recommended that this register always be programmed to zero. this register is provided for compliance with sff-8472. it is not used by the MIC3001 when doing threshold comparisons and setting alarm or warning bits. tx optical power low alarm msb (txminh) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0mw) serial address a2 h = 1010001 b byte address 26 = 1a h each lsb represents 25.6 w. this register is to be used in conjunction with txminl to yield a sixteen-bit value. the values in txminh:tminl are in an unsigned binary format. the value in t his register is uncalibrated. t he value in txminh is compared against txoph. alarm bit ax is set if txoph < txminh. tx optical power low alarm lsb (txminl) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0mw) serial address a2 h = 1010001 b byte address 27 = 1b h each lsb represents 0.1 w. this register is to be used in conjunction with txminh to yield a sixteen-bit value. the values in txoph:txopl are in an unsigned binary format. the value in this register is uncalibrated. the value in txminh is compared against txoph. alarm bit ax is set if txoph < txminh. since txopl is always zero, it is recommended that this register always be programmed to zero. this register is provided for compliance with sff-8472. it is not used by the MIC3001 when doing threshold comparisons and setting alarm or warning bits.
micrel, inc. MIC3001 august 2004 42 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 rx optical power high alarm threshold msb (rxmaxh) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0mw) serial address a2 h = 1010001 b byte address 32 = 20 h each lsb represents 25.6 w. this register is to be used in conjunction with rxmaxl to yield a sixteen-bit value. the value in this register is uncalibrated. the value in rxmaxh is comp ared against rxoph. alarm bit ax is set if rxoph > rxmaxh. rx optical power high alarm threshold lsb (rxmaxl) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0mw) serial address a2 h = 1010001 b byte address 33 = 21 h each lsb represents 0.1 w. this register is to be used in conjunction with rxmaxh to yield a sixteen-bit value. the values in rxmaxh:rxmaxl are in an unsigned binary format. the value in this register is uncalibrated. the value in rxmaxh is compared against rxoph. alarm bit ax is set if rxoph > rxmaxh. since rxopl is al ways zero, it is recommended that this register always be programmed to zero. this register is prov ided for compliance with sff-8472. it is not used by the MIC3001 when doing threshold comparisons and setting alarm or warning bits. rx optical power low alarm threshold msb (rminh) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0mw) serial address a2 h = 1010001 b byte address 34 = 22h each lsb represents 25.6 w. this register is to be used in conjunction with rxminl to yield a sixteen-bit value. the value in this register is uncalibrated. the value in rxminh is comp ared against rxoph. alarm bit ax is set if rxoph < rxminh. rx optical power low alarm threshold lsb (rminl) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0mw) serial address a2 h = 1010001 b byte address 35 = 23 h each lsb represents 0.1 w. this register is to be used in conjunction with rxminh to yield a sixteen- bit value. the values in rxminh:rxminl are in an unsigned binary format. the value in this register is uncalibrated. the value in rxminh is compared against rxoph. alarm bit ax is set if rx oph < rxminh. since rxopl is always zero, it is recommended that this register always be programmed to zero. this register is provided for compliance with sff-8472. it is not used by the MIC3001 when doing threshold comparisons and setting alarm or warning bits.
micrel, inc. MIC3001 august 2004 43 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 warning threshold registers temperature high warning threshold msb (thighh) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0c) serial address a2 h = 1010001 b byte address 04 = 04 h each lsb represents one degree centigrade. this register is to be used in conjunction with thighl to yield a sixteen-bit temperature value. the value in this register is uncalibrate d. the value in thighh is compared against temph. warning bit wx is set if temph > thighh. temperature high warning threshold lsb (thighl) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0c) serial address a2 h = 1010001 b byte address 05 = 05 h this register is to be used in conjunction with thighh to yie ld a sixteen-bit temperature value. the value in this register is uncalibrated. the value in thighh is compared against temph. warning bit wx is set if thighh > temph. since templ is always zero, it is recommended that this register always be pr ogrammed to zero. this register is provided for compliance with sff-8472. it is not used by the MIC3001 when doing th reshold comparisons and setting alarm or warning bits. temperature low warning threshold msb (tlowh) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0c) serial address a2 h = 1010001 b byte address 06 = 06 h each lsb represents one degree centigrade. this register is to be used in conjunction with tlowl to yield a sixteen-bit temperature value. the value in this register is uncalibrated. the value in tlowh is compared against temph. warning bit wx is set if temph < tlowh. temperature low warning threshold lsb (tlowl) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0c) serial address a2 h = 1010001 b byte address 07 = 07 h this register is to be used in conjunction with tlowh to yiel d a sixteen-bit temperature value. the value in this register is uncalibrated. the value in tlowh is compared against temph. warning bit wx is set if temph < tlowh. since templ is always zero, it is recommended that this register always be pr ogrammed to zero. this register is provided for compliance with sff-8472. it is not used by the MIC3001 when doing th reshold comparisons and setting alarm or warning bits.
micrel, inc. MIC3001 august 2004 44 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 voltage high warning threshold msb (vhighh) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0v) serial address a2 h = 1010001 b byte address 12 = 0c h each lsb represents 25.6mv. this register is to be used in conj unction with vhighl to yield a sixteen-bit value. the value in this register is uncalibrated. the value in vhighh is com pared against vinh. warning bit wx is set if vinh > vhighh. voltage high warning threshold lsb (vhighl) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0v) serial address a2 h = 1010001 b byte address 13 = 0d h each lsb represents 100 v. this register is to be used in conjunction with vhighh to yield a sixteen-bit value. the value in vhighh is compared against vinh. warning bit wx is set if vinh > vhighh. since vinl is always zero, it is recommended that this register always be programmed to zero. this register is provided for compliance with sff-8472. it is not used by the MIC3001 when doing threshold comparisons and setting alarm or warning bits. voltage low warning threshold msb (vlowh) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0v) serial address a2 h = 1010001 b byte address 14 = 0e h each lsb represents 25.6mv. this register is to be used in c onjunction with vlowl to yield a sixteen-bit value. the value in this register is uncalibrated. the value in vlowh is comp ared against vinh. warning bit wx is set if vinh < vlowhh. voltage low warning threshold lsb (vlowl) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0v) serial address a2 h = 1010001 b byte address 15 = 0f h each lsb represents 100 v. this register is to be used in conjunction with vlowh to yield a sixteen-bit value. the value in vlowh is compared against vinh. warning bit wx is set if vinh < vlowh. since vinl is always zero, it is recommended that this register always be programmed to zero. this register is provided for compliance with sff-8472. it is not used by the MIC3001 when doing threshold comparisons and setting alarm or warning bits.
micrel, inc. MIC3001 august 2004 45 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 bias current high warning threshold msb (ihighh) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0ma) serial address a2 h = 1010001 b byte address 20 = 14 h this register is to be used in conjunction with ihighl to yi eld a sixteen-bit value. the value in this register is uncalibrated . the value in ihighh is compared against ildh. warning bit wx is set if ildh > ihighh. bias current high warning threshold lsb (ihighl) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0ma) serial address a2 h = 1010001 b byte address 21 = 15 h each lsb represents 2 a. this register is to be used in conjunction with ih ighh to yield a sixteen-bit value. the value in this register is uncalibrated. the value in ihighh is compared agains t ildh. warning bit wx is set if ildh > ihighh. since ildl is always zero, it is recommended that this register always be pr ogrammed to zero. this register is provided for compliance with sff-8472. it is not used by the MIC3001 when doing th reshold comparisons and setting alarm or warning bits. bias current low warning threshold msb (ilowh) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0ma) serial address a2 h = 1010001 b byte address 22 = 16 h this register is to be used in conjunction with ilowl to yiel d a sixteen-bit value. the value in this register is uncalibrated. the value in ilowh is compared against ildh. wa rning bit wx is set if ildh < ilowh. bias current low warning threshold lsb (ilowl) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0ma) serial address a2 h = 1010001 b byte address 23 = 17 h each lsb represents 2 a. this register is to be used in conjunction with il owh to yield a sixteen-bit value. the value in this register is uncalibrated. the value in ilowh is compared against ildh. warning bit wx is set if ildh < ilowh. since ildl is always zero, it is recommended that this register always be pr ogrammed to zero. this register is provided for compliance with sff-8472. it is not used by the MIC3001 when doing th reshold comparisons and setting alarm or warning bits.
micrel, inc. MIC3001 august 2004 46 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 tx optical power high warning msb (txhighh) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0mw) serial address a2 h = 1010001 b byte address 28 = 1c h each lsb represents 25.6 w. this register is to be used in conjunction with txhighl to yield a sixteen-bit value. the values in txhighh:txhighl are in an unsigned binary format. the value in this register is uncalibrat ed. the value in txhighh is compared against txoph. warning bit wx is set if txoph > txhighh. tx optical power high warning lsb (txhighl) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0mw) serial address a2 h = 1010001 b byte address 29 = 1d h each lsb represents 0.1 w. this register is to be used in conjunction with txhighh to yield a sixteen-bit value. the values in txhighh:txhighl are in an unsigned binary format. the value in this register is uncalibrat ed. the value in txhighh is compared against txoph. warning bit wx is set if txoph > txhi ghh. since txopl is always zero, it is recommended that this register always be programmed to zero. this register is provided for compliance with sff-8472. it is not used by the MIC3001 when doing threshold comparisons and setting alarm or warning b. tx optical power low warning msb (tlowh) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0mw) serial address a2 h = 1010001 b byte address 30 = 1e h each lsb represents 25.6 w. this register is to be used in conjunction with txlowl to yield a sixteen-bit value. the values in txlowh:tlowl are in an unsigned binary format. the value in this register is uncalibrated. the value in txlowh is compared against txoph. warning bit wx is set if txoph < txlowh. tx optical power low warning lsb (tlowl) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0mw) serial address a2 h = 1010001 b byte address 31 = 1f h each lsb represents 0.1 w. this register is to be used in conjunction with txlowh to yield a sixteen-bit value. the values in txlowh:txlowl are in an unsigned binary format. the value in this register is uncalibrated. the value in txlowh is compared against txoph. warning bit wx is set if txoph < tx lowh. since txopl is always zero, it is recommended that this register always be programmed to zero. this register is provided for compliance with sff-8472. it is not used by the MIC3001 when doing threshold comparisons and setting alarm or warning bits.
micrel, inc. MIC3001 august 2004 47 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 rx optical power high warning threshold msb (rxhighh) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0mw) serial address a2 h = 1010001 b byte address 36 = 24 h each lsb represents 25.6 w. this register is to be used in conjunction with rxhighl to yield a sixteen-bit value. the value in this register is uncalibrated. the value in rxhighh is compar ed against rxoph. warning bit wx is set if rxoph > rxhighh. rx optical power high warning threshold lsb (rxhighl) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0mw) serial address a2 h = 1010001 b byte address 37 = 25 h each lsb represents 0.1 w. this register is to be used in conjunction with rxhighh to yield a sixteen-bit value. the values in rxhighh:rxhighl are in an unsigned binary format. the val ue in this register is uncalibrated. the value in rxhighh is compared against rxoph. warning bit wx is set if rxoph > rx highh. since rxopl is always zero, it is recommended that this register always be programmed to zero. this register is provided for compliance with sff-8472. it is not used by the MIC3001 when doing threshold comparisons and setting alarm or warning bits. rx optical power low warning threshold msb (rxlowh) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0mw) serial address a2 h = 1010001 b byte address 38 = 26 h each lsb represents 25.6 w. this register is to be used in conjunction wi th rxlowl to yield a sixteen-bit value. the value in this register is uncalibrated. the value in rxlowh is comp ared against rxoph. warning bit wx is set if rxoph < rxlowh. rx optical power low warning threshold lsb (rxlowl) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0mw) serial address a2 h = 1010001 b byte address 39 = 27 h each lsb represents 0.1 w. this register is to be used in conjunction with rxlowh to yield a sixteen-bit value. the values in rxlowh:rxlowl are in an unsigned binary format. the value in this register is uncalibrated. the value in rxlowh is compared against rxoph. warning bit wx is set if rxoph < rx lowh. since rxopl is always zero, it is recommended that this register always be programmed to zero. this register is provided for compliance with sff-8472. it is not used by the MIC3001 when doing threshold comparisons and setting alarm or warning bits.
micrel, inc. MIC3001 august 2004 48 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 checksum (chksum) checksum of bytes 0 - 94 at serial address a2h d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (0c) serial address a2 h = 1010001 b byte address 95 = 5f h this register is provided for compliance with sff-8472. it is implemented as general-purpose non-volatile memory. read/write access is possible whenever a valid oem password has been entered. chksum is read-only in user mode.
micrel, inc. MIC3001 august 2004 49 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 adc result registers temperature result msb (temph) d[7] read-only d[6] read-only d[5] read-only d[4] read-only d[3] read-only d[2] read-only d[1] read-only d[0] read-only default value 0000 0000 b = 00 h (0c) (1) serial address a2 h = 1010001 b byte address 96 = 60 h each lsb represents one degree centigrade. this register is to be used in conjunction with templ to yield a sixteen-bit temperature value. the value in this register is uncalibrated . the host should process the results using the scale factor and offset provided. see the exte rnal calibration section. temperature result lsb (templ) d[7] read-only d[6] read-only d[5] read-only d[4] read-only d[3] read-only d[2] read-only d[1] read-only d[0] read-only default value 0000 0000 b = 00 h (0c) serial address a2 h = 1010001 b byte address 97 = 61 h this register is to be used in conjunction with temph to yi eld a sixteen-bit temperature value. the value in this register is uncalibrated. the host should process the results using the scale factor and offset provided. see the external calibration section. in the MIC3001 this register will always return zero . this register is provided for compliance with sff-8472. it is n ot used by the MIC3001 when doing threshold comparisons and setting alarm or warning bits. voltage msb (vinh) d[7] read-only d[6] read-only d[5] read-only d[4] read-only d[3] read-only d[2] read-only d[1] read-only d[0] read-only default value 0000 0000 b = 00 h (0v) (2) serial address a2 h = 1010001 b byte address 98 = 62 h each lsb represents 25.6mv. this register is to be used in conj unction with vinl to yield a sixteen-bit value. the values in vinh:vlnl are in an unsigned binary format. the value in this r egister is uncalibrated. the host should process the results usi ng the scale factor and offset provided. s ee the external calibration section. voltage lsb (vinl) d[7] read-only d[6] read-only d[5] read-only d[4] read-only d[3] read-only d[2] read-only d[1] read-only d[0] read-only default value 0000 0000 b = 00 h (0v) serial address a2 h = 1010001 b byte address 99 = 63 h each lsb represents 100 v. this register is to be used in conjunction with vinh to yield a sixteen-bit value. the values in vinh:vinl are in an unsigned binary format. the value in this r egister is uncalibrated. the hos t should process the results usi ng the scale factor and offset provided. see the external calibration section. in the MIC3001, this register will always return ze ro. this register is provided for compliance with sff-8472. it is not used by the MIC3001 when doing threshold comparisons and setting alarm or warning bits. notes: 1. temph will contain measured temperature dat a after the completion of one conversion. 2. vinh will contain measured data after one a/d conversion cycle.
micrel, inc. MIC3001 august 2004 50 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 laser diode bias current msb (ildh) d[7] read-only d[6] read-only d[5] read-only d[4] read-only d[3] read-only d[2] read-only d[1] read-only d[0] read-only default value 0000 0000 b = 00 h (0ma) (3) serial address a2 h = 1010001 b byte address 100 = 64 h this register is to be used in conjunction with ildl to yield a sixteen-bit value. the values in ildh:ildl are in an unsigned b inary format. the value in this register is uncalibrated. the host s hould process the results using the scale factor and offset provi ded. see the external calibration sections. laser diode bias current lsb (ildl) d[7] read-only d[6] read-only d[5] read-only d[4] read-only d[3] read-only d[2] read-only d[1] read-only d[0] read-only default value 0000 0000 b = 00 h (0ma) serial address a2 h = 1010001 b byte address 101 = 65 h each lsb represents 2 a. this register is to be used in conjunction with ildh to yield a sixteen-bit value. the values in ildh:ildl are in an unsigned binary format. the value in this regis ter is uncalibrated. the host should process the results usi ng the scale factor and offset provided. see the external calibration section. in the MIC3001, this register will always return ze ro. this register is provided for compliance with sff-8472. it is not used by the MIC3001 when doing threshold comparisons and setting alarm or warning bits. transmitted optical power msb (txoph) (4) d[7] read-only d[6] read-only d[5] read-only d[4] read-only d[3] read-only d[2] read-only d[1] read-only d[0] read-only default value 0000 0000 b = 00 h (0mw) (5) serial address a2 h = 1010001 b byte address 102 = 66 h each lsb represents 25.6 w. this register is to be used in conjunction wi th txopl to yield a sixteen-bit value. the values in txoph:txopl are in an unsigned binary format. the value in this register is uncalibrated. the host should process the results using the scale factor and offset provided. see the external calibration section. transmitted optical power lsb (txopl) d[7] read-only d[6] read-only d[5] read-only d[4] read-only d[3] read-only d[2] read-only d[1] read-only d[0] read-only default value 0000 0000 b = 00 h (0mw) serial address a2 h = 1010001 b byte address 103 = 67 h each lsb represents 0.1 w. this register is to be used in conjunction with txoph to yield a sixteen-bit value. the values in txoph:txopl are in an unsigned binary format. the value in this register is uncalibrated. the host should process the results using the scale factor and offset provided. see the external calibration section. in the MIC3001, this register will always ret urn zero. this register is provided for compliance with sff-8472. it is not used by the MIC3001 when doing threshold comparisons and setting alarm or warning bitsection. notes: 3. ildh will contain measured data after one a/d conversion cycle. 4. the scale factor corresponding to the sense resist or used must be set in the configuration register. 5. txoph will contain measured data after one a/d conversion cycle.
micrel, inc. MIC3001 august 2004 51 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 received optical power msb (rxoph) d[7] read-only d[6] read-only d[5] read-only d[4] read-only d[3] read-only d[2] read-only d[1] read-only d[0] read-only default value 0000 0000 b = 00 h (0mw) (6) serial address a2 h = 1010001 b byte address 104 = 68 h each lsb represents 25.6 w. this register is to be used in conjunction with rxopl to yield a sixteen-bit value. the values in rxoph:rxopl are in an unsigned binary format. the value in this register is uncalibrated. the host should process the results using the scale factor and offset provided. see the external calibration section. received optical power lsb (rxopl) d[7] read-only d[6] read-only d[5] read-only d[4] read-only d[3] read-only d[2] read-only d[1] read-only d[0] read-only default value 0000 0000 b = 00 h (0mw) (6) serial address a2 h = 1010001 b byte address 105 = 69 h each lsb represents 0.1 w. this register is to be used in conjunction with rxoph to yield a sixteen-bit value. the values in rxoph:rxopl are in an unsigned binary format. the value in this register is uncalibrated. the host should process the results using the coefficients provided. see the exte rnal calibration section. this register is provided for compliance with sff-8472. it is not used by the MIC3001 when doing threshold comparisons and setting alarm or warning bits. control and status (cntrl) d[7] txdis read-only d[6] stxdis read/write d[5] reserved d[4] rsel read/write d[3] srsel read/write d[2] xflt read-only d[1] los read-only d[0] por read-only default value 0000 0000 b = 00 h serial address a2 h = 1010001 b byte address 110 = 6e h bit(s) function operation d[7] txdis reflects the stat e of the txdisable pin 1 = disabled, 0 = enabled, read only. d[6] stxdis soft transmit disable 1 = disabled; 0 = enabled. d[5] d[5] reserved reserved - always write as zero. d[4] rsel reflects the state of the rsel pin 1 = high; 0 = low. d[3] srel soft rate select 1 = high (2gbps); 0 = low (1gbps). d[2] txflt reflects the state of the tx fault pin 1 = high (fault); 0 = low (no fault). d[1] los loss of signal. reflects the state of the los pin 1 = high (loss of signal); 0 = low (no loss of signal). d[0] por MIC3001 power-on status 0 = por complete, analog data ready; 1 = por in progress. notes: 6. rxoph will contain measured data after one a/d conversion cycle.
micrel, inc. MIC3001 august 2004 52 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 alarm flags alarm register 0 (alarm0) d[7] a7 read-only d[6] a6 read-only d[5] a5 read-only d[4] a4 read-only d[3] a3 read-only d[2] a2 read-only d[1] a1 read-only d[0] a1 read-only default value 0000 0000 b = 00 h (no events pending) serial address a2 h = 1010001 b byte address 112 = 70 h the power-up default value is 00 h . following the first a/d conversion, however, any of the bits may be set depending on the results. bit(s) function operation d[7] a7 high temperature alarm, temph > tm axh. 1 = condition exists, 0 = normal/ok. d[6] a6 low temperature alarm, temph < tm inh. 1 = condition exists, 0 = normal/ok. d[5] a5 high voltage alarm, vinh > vmax h. 1 = condition exists, 0 = normal/ok. d[4] a4 low voltage alarm, vinh < vmin h. 1 = condition exists, 0 = normal/ok. d[3] a3 high laser diode bias alarm, ibiash > imaxh. 1 = condition exists, 0 = normal/ok. d[2] a2 low laser diode bias alarm, ibiash < iminh. 1 = condition exists, 0 = normal/ok. d[1] a1 high transmit optical power alarm, txoph > txmaxh. 1 = condition exists, 0 = normal/ok. d[0] a0 low transmit optical power alarm, txoph < txminh. 1 = condition exists, 0 = normal/ok. alarm register 1 (alarm1) d[7] a15 read-only d[6] a14 read-only d[5] reserved d[4] reserved d[3] reserved d[2] reserved d[1] reserved d[0] reserved default value 0000 0000 b = 00 h (no events pending) serial address a2 h = 1010001 b byte address 113 = 71 h the power-up default value is 00 h . following the first a/d conversion, however, any of the bits may be set depending on the results. bit(s) function operation d[7] a15 high received power (overload) alarm, rxoph > rxmaxh. 1 = condition exists, 0 = normal/ok. d[6] a14 low received power (los) alarm, rxoph < rxminh. 1 = condition exists, 0 = normal/ok. d[5:0] reserved reserved - always write as zero.
micrel, inc. MIC3001 august 2004 53 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 warning flags warning register 0 (warn0) d[7] w7 read-only d[6] w6 read-only d[5] w5 read-only d[4] w4 read-only d[3] w3 read-only d[2] w2 read-only d[1] w1 read-only d[0] w1 read-only default value 0000 0000 b = 00 h (no events pending) serial address a2 h = 1010001 b byte address 116 = 74 h the power-up default value is 00 h . following the first a/d conversion, however, any of the bits may be set depending on the results. bit(s) function operation d[7] w7 high temperature warning, temph > thighh. 1 = condition exists, 0 = normal/ok. d[6] w6 low temperature warning, temph < tlowh. 1 = condition exists, 0 = normal/ok. d[5] w5 high voltage warning, vinh > vh ighh. 1 = condition exists, 0 = normal/ok. d[4] w4 low voltage warning, vinh < vl owh. 1 = condition exists, 0 = normal/ok. d[3] w3 high laser diode bias warning, ibiash > ihighh. 1 = condition exists, 0 = normal/ok. d[2] w2 low laser diode bias warning, ibiash < ilowh. 1 = condition exists, 0 = normal/ok. d[1] w1 high transmit optical power warning, txoph > txhighh. 1 = condition exists, 0 = normal/ok. d[0] w0 low transmit optical power warning, txoph < txlowh. 1 = condition exists, 0 = normal/ok. warning register 1 (warn1) d[7] w15 read-only d[6] w14 read-only d[5] read-only d[4] read-only d[3] read-only d[2] read-only d[1] read-only d[0] read-only default value 0000 0000 b = 00 h (no events pending) serial address a2 h = 1010001 b byte address 117 = 75 h the power-up default value is 00 h . following the first a/d conversion, however, any of the bits may be set depending on the results. bit(s) function operation d[7] w15 received power high warning, rxoph > rxhighh. 1 = condition exists, 0 = normal/ok. d[6] w14 received power low warning, rxoph < rxminh. 1 = condition exists, 0 = normal/ok. d[5:0] reserved reserved - always write as zero.
micrel, inc. MIC3001 august 2004 54 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 oem password entry (oempw) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h (reset to zero at power-on) serial address a2 h = 1010001 b byte address 120 ? 123 = 78 h - 7b h (msb is 7b h ) this four-byte field is for entry of the password required to access the oem area of the MIC3001?s memory and registers. a valid oem password will also permit access to the user areas of memory. the byte at address 123 (7b h ) is the most significant byte. this field is compared to the four-byte oempwset field at serial address a6h, bytes 12 to 15. if the two fields match, access is allowed to the oem areas of the mic30 01 non-volatile memory at serial addresses a4 h and a6 h . the oem password is set by writing the new value into oempwset. the passwor d comparison is performed following the write to the msb, address 7b h . this byte must be written last! a four-byte burst-write sequence to address 78 h may be used as this will result in the msb being written last. the new password will not take effect until after a power-on reset occu rs or a warm reset is performed using the rst bit in oemcfg0. this allows the new password to be verified before it takes effec t. this field is reset to all zeros at power on. any values wr itten to these locations will be readable by the host regardless of t he locked/unlocked status of the device. if oempwset is set to zero (00000000 h ), the MIC3001 will remain unlocked regardless of the co ntents of the oempw field. t his is the factory default security setting. byte weight 3 oem password entry, most significant byte (address = 7bh) 2 oem password entry, 2nd most significant byte (address = 7ah) 1 oem password entry, 2nd least significant byte (address = 79h) 0 oem password entry, least significant byte (address = 78h) user password setting (usrpwset) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h serial address a2 h = 1010001 b byte address 250 = fa h this register is for setting the password required to access the user area of the MIC3001?s memory and registers. this field is compared to the usrpw field at serial address a2 h , byte 251. if the two fields match, access is allowed to the user areas of the MIC3001 non-volatile memory at serial addresses a0h and a 2h. if a valid user password has not been entered, writes to the serial id fields, usrctrl, and the user scratchpad areas of a0 h and a2 h will not be allowed, and usrpwset will be unreadable (returns all zeroes). a user password is set by writing the new value into usrpwset. the new password will not take effect until after a power-on reset occurs or a warm reset is performed using the rst bit in oemcfg0. this allows the new password to be verified before it takes effect. this register is non-volatile and will be ma intained through power and reset cycles. a valid user or oem password is required for access to this register. otherwise, this register will read as 00 h . note: a valid oem password overrides the user password setting. if a valid oem password is currently in place, the user password will have no effect.
micrel, inc. MIC3001 august 2004 55 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 user password (usrpw) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h serial address a2 h = 1010001 b byte address 251 = fb h user passwords are entered in this field. this field is compared to the usrpwset field at serial address a2h, byte 250. if the two fields match, access is allowed to the user areas of t he MIC3001 non-volatile memory at serial addresses a0h and a2h. if a valid user password has not been entered, writes to the serial id fields and user scratchpad areas of a0h and a2h will not be allowed and usrpwset will be unreadable (returns all zeroes). power-on hours msb (pohh) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h serial address a2 h = 1010001 b byte address 252 = fc h the lower seven bits of this register c ontain the most-significant bits of the 15-bit power-on hours measurement. pohflt is an error flag. the value in this register should be combined with the power-on hours, low byte, pohl, to yield the complete resul t. if pohflt is set, the power-on hour meter data has been corrupt ed and should be ignored. it is recommended that a two-byte (or more) sequential read operation be performed on pohh and pohl to insure coherency between the two registers. this register is non-volatile and will be maintained through power and reset cycle. bit(s) function operation d[7] power-on hours fault flag 1 = fault; 0 = no fault. d[6:0] power-on hours, high byte non-volatile. power-on hours lsb (pohl) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write poh fault flag (pohflt) default value 0000 0000 b = 00 h serial address a2 h = 1010001 b byte address 253 = fd h this register contains the l east-significant eight bits of the 15-bit power-on hours measurement. the value in this register s hould be combined with the power-on hours, hi gh byte, pohh, to yield the complete result. if pohflt is set, the power-on hour meter data has been corrupted and should be ignored. it is recomme nded that a two-byte (or more) sequential read operation be performed on pohh and pohl to insure coherency between the tw o registers. this register is non-volatile and will be maintained through power and reset cycles.
micrel, inc. MIC3001 august 2004 56 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 data ready flags (datardy) d[7] trdy read/write d[6] vrdy read/write d[5] irdy read/write d[4] txrdy read/write d[3] rxdy read/write d[2] reserved d[1] reserved d[0] reserved default value 0000 0000 b = 00 h serial address a2 h = 1010001 b byte address 254 = fe h when the a/d conversion for a given paramet er is completed and the results availab le to the host, the corresponding data ready flag will be set. the flag will be cleared when the host reads the corresponding result register. bit(s) function operation d[7] trdy temperature data ready flag 0 = old data; 1 = new data ready d[6] vrdy voltage data ready fl ag 0 = old data; 1 = new data ready d[5] irdy bias current data read y flag 0 = old data; 1 = new data ready d[4] txrdy transmit power data ready flag 0 = old data; 1 = new data ready d[3] rxrdy receive power data ready flag 0 = old data; 1 = new data ready d[2:0] reserved reserved user control register (usrctl) d[7] read/write d[6] porm read/write d[5] pors read/write d[4] ie read/write d[3] apcsel read/write d[2] read/write d[1] read/write d[0] read/write default value 0010 0000 b = 20 h serial address a2 h = 1010001 b byte address 255 = ff h this register provides for control of the nominal apc setp oint and management of interrupts by the end-user. apcsel[1:0] select which of the apc setpoint registers, apcset0, apc set1, or apcset2 are used as the nominal automatic power control setpoint. ie must be set for any interrupts to occur. if porm is set, the power-on event will generate an interrupt and warm resets using rst will not generate a por interrupt. when a power-on interr upt occurs, assuming porm=1, pors will be set. pors will be cleared and the interrupt output de-asserted when usrctl is read by the host. if ie is set while /int is asserted, /int will be de-asserted. the host must still clear the va rious status flags by reading them. if porm is set following the setting of pors, pors will remain set, and /int will not be de-asserted, until usrctl is read by the host. porm, ie, and apcsel are non-volatile and will be maintai ned through power and reset cycles. a valid user password is required for access to this register. bit function operation d[7] reserved always write as zero; reads undefined. d[6] porm power-on interrupt mask 1 = por interrupts enabled; 0 = disabled; read/write; non-volatile. d[5] pors power-on interrupt flag 1 = por interrupt occurred; 0 = no por interrupt; read-only. d[4] ie global interrupt enable 1 = enabled; 0 = disabled; read/write; non-volatile. d[3] apcsel selects apc setpoint register 00 = apcset0, 01 = apcset1, 10 = apcset2; 11 = reserved; read/write; non-volatile. d[2:0] reserved reserved
micrel, inc. MIC3001 august 2004 57 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 oem configuration register 0 (oemcfg0) d[7] rst write only d[6] zone read/write d[5] dflt read only d[4] oe reserved d[3] modref reserved d[2] vaux[2] read/write d[1] vaux[1] read/write d[0] vaux[0] read/write default value 0000 0000 b = 00 h serial address a6 h = 1010011 b byte address 00 = 00 h a write to oemcfg0 will result in any a/d conversion in progress being aborted and the result discarded. the a/d will begin a new conversion sequence once the write operation is complete . all bits in oemcfg0 are non-volatile except dflt and rst. a valid oem password is required for access to this register. bit(s) function operation d[7] rst 0 = no action; 1 = reset; write-only. d[6] zone selects temperature zone. 0 = internal; 1 = external; non-volatile. d[5] dflt diode fault flag. 1 = diode fault; 0 = ok. d[4] oe output enable for shdn, v mod , and v bias . 1 = enabled; 0 = hi-z; non-volatile. d[3] modref selects whether v mod is referenced to ground or v dd . 1 = v dd ; 0 = gnd; non-volatile. d[2:0] vaux[2:0] selects the voltage reported in vinh:vinl. 000 = v in ; 001 = v dda ; 010 = v bias ; 011 = v mod ; 100 = apcdac; 101 = moddac; 110 = fltdac; non-volatile oem configuration register 1 (oemcfg1) d[7] inv read/write d[6] gain read/write d[5] biasref read/write d[4] rfb[2] read/write d[3] rfb[1] read/write d[2] rfb[0] read/write d[1] srce read/write d[0] spol read/write default value 0000 0000 b = 00 h serial address a6 h = 1010011 b byte address 1 = 01 h a write to oemcfg1 will result in any a/d conversion in progress being aborted and the result discarded. the a/d will begin a new conversion sequence once the write operation is complete . all bits in oemcfg1 are non-volatile and will be maintained through power and reset cycles. a valid oem password is required for access to this register.
micrel, inc. MIC3001 august 2004 58 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 bit(s) function operation d[7] inv inverts the apc op-amp inputs. when set to ?0? the bias dac output is connected to the ?+?input and fb is connected to the ??? input of the op amp. set to ?0? to use the adc feedback loop. 0 = emitter follower (no inversion); 1 = common emitter (inverted); read/write; non-volatile. d[6] gain sets the feedback voltage range by changing the apcdac output swing; 0-v ref for optical feedback, 0-v ref /4 for electrical feedback. 1 = v ref /4 full scale; 0 = v ref full scale; read/write; non-volatile. d[5] biasref selects whether fb and vmpd are referenced to ground or v dd and selects feedback resistor termination voltage (v dda or gnda). 1 = v dd ; 0 = gnd; read/write; non-volatile. d[4:2] rfb[2:0] selects internal feedback resistance. (resistors will be terminated to v dda or gnda according to biasref.) 000 = ; 001 = 800 ? , 010 = 1.6k ? , 011 = 3.2k ? , 100 = 6.4k ? , 101 = 12.8k ? , 110 = 25.6k ? , 111 = 51.2k ? ; read/write; non-volatile. d[1] srce v bias source vs. sink drive. 1 = source (npn), 0 = sink (pnp); read/write; non-volatile. d[0] spol polarity of shutdown output, shdn, when active. 1 = high; 0 = low; read/write; non-volatile. oem configuration register 2 (oemcfg2) d[7] i2cadr[3] read/write d[6] i2cadr[2] read/write d[5] i2cadr[1] read/write d[4] i2cadr[0] read/write d[3] lutoff read/write d[2] lutoff read/write d[1] lutoff read/write d[0] lutoff read/write default value 1010 xxxx b = xx h (slave address = 1010xxx b ) serial address a6 h = 1010011 b byte address 2 = 02 h caution: changes to i2cadr take effect immediately! any accesses following a write to i2cadr must be to the newly programmed serial bus address. a valid oem password is required fo r access to this register. this register is non-volatile and will be maintained through power and reset cycles. bit(s) function operation d[7:4] i2cadr[3:0] upper four msbs of the serial bus slave address; writes take effect immediately. read/write; non-volatile. d[3:0] lutoff lut offset. lutoff is added to the result of the digital temperature sensor to derive the table index; writes take effect after reset. read/write; non-volatile.
micrel, inc. MIC3001 august 2004 59 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 apc setpoint 0 (apcset0) automatic power control setpoint (unsigned binary) used when apcsel[1:0] = 00 d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h serial address a6 h = 1010011 b byte address 3 = 03 h when a.p.c. is on, i.e., the apccal bit in oemcal0 is set, t he value in apcsetx is added to the signed value taken from the a.p.c. look-up table and loaded into the vbias dac. when a.p.c. is off, the value in apcset is loaded directly into the vbias dac, bypassing the look-up table entirely. in either case, the vbias dac setting is reported in the vbias register. the apccfg bits determine the dac?s response to higher or lower numeric values. a valid oem password is required for access to this register. this register is non-volatile and will be maintained through power and reset cycles. apc setpoint 1 (apcset1) automatic power control setpoint (unsigned binary) used when apcsel[1:0] = 01 d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h serial address a6 h = 1010011 b byte address 4 = 04 h when a.p.c. is on, i.e., the apccal bit in oemcal0 is set, t he value in apcsetx is added to the signed value taken from the a.p.c. look-up table and loaded into the vbi as dac. when a.p.c. is off, the value in apcset is loaded directly into the vbias dac, bypassing the look-up table entirely. in either case, the vbias dac setting is reported in the vbias register. the apccfg bits determine the dac?s response to higher or lower numeric values. a valid oem password is required for access to this register. this register is non-volatile and will be maintained through power and reset cycles. apc setpoint 2 (apcset2) automatic power control setpoint (unsigned binary) used when apcsel[1:0] = 10 d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h serial address a6 h = 1010011 b byte address 5 = 05 h when a.p.c. is on, i.e., the apccal bit in oemcal0 is set, t he value in apcsetx is added to the signed value taken from the a.p.c. look-up table and loaded into the vbi as dac. when a.p.c. is off, the value in apcset is loaded directly into the vbias dac, bypassing the look-up table entirely. in either case, the vbias dac setting is reported in the vbias register. the apccfg bits determine the dac?s response to higher or lowe r numeric values. this register is non-volatile and will be maintained through power and reset cycles. a valid oem password is required for access to this register. modulation dac setting (modset) nominal v mod setpoint d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h serial address a6 h = 1010011 b byte address 6 = 06 h when a.p.c. is on, the value correspondin g to the current temperature is taken from the modlut look-up table, added to modset and loaded into the v mod dac. this register is non-volatile and will be maintained through power and reset cycles. a valid oem password is required for access to this register.
micrel, inc. MIC3001 august 2004 60 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 i bias fault threshold (ibflt) bias current fault threshold d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h serial address a6 h = 1010011 b byte address 7 = 07 h a valid oem password is required for acce ss to this register. this register is non-volatile and will be maintained through powe r and reset cycles. a fault is generated if the bias curre nt is higher than ibflt value set in this register. transmit power fault threshold (txflt) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h serial address a6 h = 1010011 b byte address 8 = 08 h a valid oem password is required for acce ss to this register. this register is non-volatile and will be maintained through powe r and reset cycles. a fault is generated if the transmit po wer is higher than txflt value set in this register. loss-of-signal threshold (losflt) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h serial address a6 h = 1010011 b byte address 9 = 09 h a valid oem password is required for acce ss to this register. this register is non-volatile and will be maintained through pow er and reset cycles. a fault is generated if the received po wer is lower than losflt value set in this register. byte function operation d[7:4] receive loss-of-signal th reshold read/write; non-volatile.
micrel, inc. MIC3001 august 2004 61 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 fault suppression timer (flttmr) fault suppression interval in increments of 0.5ms d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h serial address a6 h = 1010011 b byte address 10 = 0a h saturation faults are suppressed for a time, t flttmr , following laser turn-on. this avoids nuisance tripping while the apc loop starts up. the length of this interval is (flttmr 0.5ms), typical. a value of zero will result in no fault suppression. a valid oem password is required for access to this register. this regist er is non-volatile and will be maintained through power and reset cycles. fault mask (fltmsk) d[7] oemim read/write d[6] pohe read/write d[5] reserved d[4] reserved d[3] satmsk read/write d[2] txmsk read/write d[1] iamsk read/write d[0] dfmsk read/write default value 0000 0000 b = 00 h serial address a6 h = 1010011 b byte address 11 = 0b h a valid oem password is required for acce ss to this register. this register is non-volatile and will be maintained through powe r and reset cycles. bit function operation d[7] oemim oem interrupt mask bit 1 = ma sked; 0 = enabled; read/write; non-volatile. d[6] pohe oem power-on hour meter enable bit 1 = enabled; 0 = disabled; read/write; non-volatile. d[5:4] d[5:4] reserved always write as zero; reads undefined. d[3] satmsk apc saturation fault mask bit 1 = masked; 0 = enabled; read/write; non-volatile. d[2] txmsk high tx optical power fault mask bit 1 = masked; 0 = enabled; read/write; non-volatile. d[1] iamsk bias current high alarm mask bit 1 = masked; 0 = enabled; read/write; non-volatile. d[0] dfmsk diode fault mask bit 1 = mask ed; 0 = enabled; read/write; non-volatile. oem password setting (oempwset) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h serial address a6 h = 1010011 b byte address 12 - 15 = 0f h - 0f h ; 0c h = msb this four-byte field is the password required for access to the oem area of the MIC3001?s memory and registers. the byte at address 250 (fa h ) is the most significant byte. this field is com pared to the four-byte oempw field at serial address a2 h , byte 120 to 123. if the two fields match, access is allowed to the oe m areas of the MIC3001 non-volatile memory at serial addresses a4 h and a6 h . the oem password may be set by writing the new value into oempwset. the new password will not take effect until after a power-on reset occurs or a warm reset is performed using the rst bit in oemcfg0. this allows the new password to be verified before it take s effect. these registers are non-volatile and wi ll be maintained through power and reset cycles. a valid oem password is required for access to this register.
micrel, inc. MIC3001 august 2004 62 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 byte weight 3 oem password, most significant byte 2 oem password, 2nd most significant byte 1 oem password, 2nd least significant byte 0 oem password, least significant byte oem calibration 0 (oemcal0) d[7] reserved d[6] fltdis read/write d[5] fspin read/write d[4] wrinh read/write d[3] apccal read/write d[2] frcint read/write d[1] frctxf read/write d[0] frclos read/write default value 0000 0000 b = 00 h serial address a6 h = 1010011 b byte address 16 = 10 h a valid oem password is required for access to this register. bit function operation d[7] reserved always write as zero; reads undefined. d[6] fltdis fault comparator disable; inhibits output of fault comparators when set. 0 = faults enabled; 1 = disabled; read/write. d[5] fspin fault comparator ?spin-on-channel? mode select; do not enable adc and fc spin-on-channel modes simultaneously. 0 = normal operation; 1 = spin on channel; read/write. d[4] wrinh inhibit nvram write cycles. 0 = nor mal operation; 1 = inhibit writes; read/write. d[3] apccal selects apc calibration mode - dacs may be controlled directly. 0 = normal mode; 1 = calibration mode; read/write. d[2] frcint forces the assertion of /int 0 = normal operation; 1 = asserted; read/write. d[1] frctxf forces the assertion of txfault 0 = normal operation; 1 = asserted; read/write. d[0] fdclos forces the assertion of rxlos 0 = normal operation; 1 = asserted; read/write. oem calibration 1 (oemcal1) d[7] reserved d[6] adstp read/write d[5] adidl read/write d[4] 1shot read/write d[3] adspin read/write d[2] spin[2] read/write d[1] spin[1] read/write d[0] spin[0] read/write default value 0000 0000 b = 00 h serial address a6 h = 1010011 b byte address 17 = 11 h a valid oem password is required for access to this register.
micrel, inc. MIC3001 august 2004 63 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 bit function operation d[7] reserved always write as zero; reads undefined. d[6] adstp stop adc halts the analog to digital converter 0 = normal operation; 1 = stopped; read/write. d[5] adidl adc idle flag 0 = busy; 1 = idle; read/write. d[4] 1shot triggers one-shot a/d conversion cycle 0 = normal operation; 1 = one-shot; read/write. d[3] adspin selects adc spin-on-channel mode; do not enable adc and fc spin-on- channel modes simultaneously 0 = normal operation; 1 = spin -on-channel; read/write. d[2], d[1], d[0] spin[2:0] adc and fault comparator (fc) channel select for spin-on-channel mode; do not enable adc and fc spin-on-channel modes simultaneously adc: 000 = temperature; 001 = voltage; 010 = vild; 011 = vmpd; 100 = vrx; fc: 001 = vild; 001 = vmpd; 010 = vrx; read/write. oem calibration 1 (oemcal1) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h serial address a6 h = 1010011 b byte address 18 = 12h the look-up table index is derived from the current temperature measurement and lutoff as follows: where t avg (n) is the current average temperature. this register allows the current table index to be read by the host. the table base address must be added to lutindx to form a complete table index in physical memory. a valid oem password is required for access to this register. otherwise, reads are undefined. oem configuration 3 (oemcfg3) d[7] lutsel read/write d[6] txfpol read/write d[5] gpod read/write d[4] gpom read/write d[3] gpoc read/write d[2] txfin read/write d[1] losdis read/write d[0] intcal read/write default value 0000 1000 b = 08 h serial address a6 h = 1010011 b byte address 19 = 13 h this register is non-volatile and will be maintained through po wer and reset cycles. a valid oem password is required for acces s to this register. gpod and gpoc are ignored when gpom = 0. txfpol is ignored if txfin = 0.
micrel, inc. MIC3001 august 2004 64 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 bit function operation d[7] lutsel rx power look-up table input selection bit 1 = rx power; 0 = temperature; read/write; ignored if intcal = 0. d[6] txfpol txfin active polarity select; a fault is indicated when txfin = txfpol 0 = active-low; 1 = active-high; read/write; ignored if txfin = 0. d[5] gpod gpo output drive 0 = open drain; 1 = push-pull; read/write; ignored if gpom = 0. d[4] gpom gpo/rsout mode select 0 = rsout; 1 = gpo; read/write. d[3] gpoc gpo output control 0 = low; 1 = high; read/write; ignored if gpom = 0. d[2] txfin txfin mode select 0 = shdn; 1 = txfin; read/write. d[1] losdis rxlos comparator disable 0 = enabled; 1 = disabled; read/write. d[0] intcal calibration mode select 0 = external calibration; 1 = internal calibration; read/write. bias dac setting (apcdac) current vbias setting d[7] read only d[6] read only d[5] read only d[4] read only d[3] read only d[2] read only d[1] read only d[0] read only default value 0000 0000 b = 00 h serial address a6 h = 1010011 b byte address 20 = 14 h this register reflects (reads back) the value set in the apc register (apcset0, apcset1, or apcset2 whichever is selected). a valid oem password is required for access to this register. modulation dac setting (moddac) current vmod setting d[7] read only d[6] read only d[5] read only d[4] read only d[3] read only d[2] read only d[1] read only d[0] read only default value 0000 0000 b = 00 h serial address a6 h = 1010011 b byte address 21 = 15 h this register reflects (reads back) the value set in the modset register. a valid oem password is required for access to this register. oem readback register (oemrd) d[7] reserved d[6] reserved d[5] reserved d[4] int read only d[3] apcsat read only d[2] ibflt read only d[1] txflt read only d[0] rsout read only default value 0000 0000 b = 00 h serial address a6 h = 1010011 b byte address 22 = 16 h this register reflects (reads back) the status of the bits co rresponding to the parameters defined below. a valid oem password is required for access to this register. otherwi se, reads are undefined and writes are ignored.
micrel, inc. MIC3001 august 2004 65 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 bit function operation d[7:5] reserved always write as zero; reads undefined. d[4] int mirrors state of /int but active-high; not state of physical pin! 1 = interrupt; 0 = no interrupt. d[3] apcsat apc saturation fault comparator output state 1 = fault; 0 = normal operation. d[2] ibflt state of ibias over-current fault comparator output 1 = fault; 0 = normal operation; read-only. d[1] txflt state of transmit power fault comparator output 1 = fault; 0 = normal operation; read-only. d[0] rsout state of the rate select output pin, rsout 1 = high; 0 = low; read-only. signal detect threshold (losfltn) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h serial address a6 h = 1010011 b byte address 23 = 17 h this register works in conjunction with the losflt register to control the operation of the los s of signal comparator. the comparator?s output, rxlos, is asserted when the input on vrx falls below the level in losflt. the output will then be de- asserted when the vrx signal rises above losfltn. the input signal is subject to scaling by the rxpot. if the los comparator is disabled, i.e., losdis = 1, this register is i gnored. a valid oem password is required for access to this registe r. this register is non-volatile and will be maintained through power and reset cycles. rx eepot tap selection (rxpot) d[7] reserved d[6] reserved d[5] reserved d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h serial address a6 h = 1010011 b byte address 24 = 18 h this register is non-volatile and will be maintained through po wer and reset cycles. a valid oem password is required for acces s to these registers. bit(s) function operation d[7:5] reserved reserved. always write as zero; reads undefined. d[4:0] rxpot tap selection: 00000 = no divider action; pot disconnected 00001 = 31/32 00010 = 30/32 ? ? ? 11110 = 2/32 11111 = 1/32 read/write; non-volatile.
micrel, inc. MIC3001 august 2004 66 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 oem configuration 4 (oemcfg4) d[7] reserved d[6] reserved d[5] reserved d[4] reserved d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h serial address a6 h = 1010011 b byte address 25 = 19 h this register is non-volatile and will be maintained through po wer and reset cycles. a valid oem password is required for acces s to these registers. bit(s) function operation d[7:5] reserved reserved. always write as zero; reads undefined. i start [3:0] i start current level selection: 0000 = no i start current 0001 - 1111 = 0.375ma x i start [3:0] i start is used to speed up the laser start-up after a fault accures. the charging current of the compensation cap starts from i start instead of ramping up from 0. read/write; non-volatile. power-on hour meter data (pohdata) d[7] read/write d[6] read/write d[5] read/write d[4] read/write d[3] read/write d[2] read/write d[1] read/write d[0] read/write default value 0000 0000 b = 00 h serial address a6 h = 1010011 b byte address 32-39 = 20 h - 27 h these registers are used for backing up the poh result during powe r cycles. at power-up, the poh meter selects the larger of the two values as the initial count. incremental results are st ored in alternate register pairs. the power-on hour meter may be reset or preset by writing to these registers. these regist ers are non-volatile and will be maintained through power and reset cycles. a valid oem password is required for access to these registers. byte weight 3 poha, high-byte 2 poha, low-byte 1 pohb, high-byte 0 pohb, low-byte oem scratchpad registers (scratchn) default value 0000 0000 b = 00 h serial address a6 h = 1010011 b byte address scratch0: 126 = 7e h scratch1: 127 = 7f h scratch2: 128 = 80 h ....................................... scratch127: 253 = fd h the scratchpad registers are general-purpose non-volatile memory locations. they can be freely read from and written to any time the MIC3001 is in oem mode.
micrel, inc. MIC3001 august 2004 67 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 rx power look-up table (rxlutn) default value 0000 0000 b = 00 h serial address a6 h = 1010011 b byte address 40-71 = 28 h - 47 h these registers are non-volatile and will be maintained through power and reset cycles. a valid oem password is required for access to these registers. bytes definition rxslp0h rx slope 0, high byte. rxslp0l rx slope 0, low byte. rxoff0h rx offset 0, high byte. rxoff0l rx offset 0, low byte. rxslp1h rx slope 1, high byte. rxslp1l rx slope 1, low byte. rxoff1h rx offset 1, high byte. rxoff1l rx offset 1, low byte. ? ? ? ? ? ? rxslp7h rx slope 7, high byte. rxslp7l rx slope 7, low byte. rxoff7h rx offset 7, high byte. rxoff7l rx offset 7, low byte. calibration constants (caln) default value 0000 0000 b = 00 h serial address a6 h = 1010011 b byte address 74 - 87 = 4a h - 57h these registers are non-volatile and will be maintained through power and reset cycles. a valid oem password is required for access to these registers. bytes definition toffh temperature offset, high byte. toff0l temperature offset, low byte. always reads zero; writes ignored. vslp0h voltage slope, high byte. vslp0l voltage slope, low byte. voffh voltage offset, high byte. voff0l voltage offset, low byte. islp0h bias current slope, high byte. islp0l bias current slope, low byte. ioffh bias current offset, high byte. ioff0l bias current offset, low byte. txslph tx power slope, high byte. txslpl tx power slope, low byte. txoffh tx power offset, high byte. txoffl tx power offset, low byte.
micrel, inc. MIC3001 august 2004 68 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 manufacturer id register (mfg_id) identifies micrel as the manufacturer of the device. always returns 2ah d[7] read only d[6] read only d[5] read only d[4] read only d[3] read only d[2] read only d[1] read only d[0] read only default value 0000 0000 b = 00 h serial address a6 h = 1010011 b byte address 32-39 = 20 h - 27 h these registers are used for backing up the poh result during powe r cycles. at power-up, the poh meter selects the larger of the two values as the initial count. incremental results are st ored in alternate register pairs. the power-on hour meter may be reset or preset by writing to these registers. these regist ers are non-volatile and will be maintained through power and reset cycles. a valid oem password is required for access to these registers. bit(s) function operation d[7:0] identifies micrel as the ma nufacturer of the device. always returns 2a h . read only. always returns a h device id register (dev_id) d[7] read only d[6] read only d[5] read only d[4] read only d[3] read only d[2] read only d[1] read only d[0] read only MIC3001 device id always reads 0 at d[ 5-7] and 1 at d[4] die revision default value 0001 xxxx b = 1x h serial address a6 h = 1010011 b byte address 255 = ff h the value in this register, in combination with the mfg_id regis ter, serve to identify the MIC3001 and its revision number to software. this register is read-only.
micrel, inc. MIC3001 august 2004 69 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 applications information controlling laser diode bias figure 26. example apc circuit for common-cathode tosa figure 27. example apc circuit for common anode tosa
micrel, inc. MIC3001 august 2004 70 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 choosing c comp the apc loop is compensated by a capacitor, c comp , connected from comp to either v dda or gnda. this capacitor adjusts the slew rate and bandwidth of the loop as follows: where: i slew = 64a, g m = 125mho these relationships are shown graphically in figure 28 and figure 29. figure 28. slew rate vs. c comp value figure 29. open loop unity-gain bandwidth vs. c comp the loop response should be tailored to the data rate, encoding format and maximum run-lengths, and required laser turn-on time. higher data rates and/or shorter maximum run lengths and/or faster turn-on times call for smaller capacitors. lower data rates and/or longer maximum run lengths and/or slower turn-on times call for larger capacitors. in order to meet the sfp/gbic turn-on requirement of 1ms, for example, do not employ a capacitor larger than 20nf. low esr capacit ors such as ceramics will give the best results. ex cessive esr will reduce the effectiveness of c comp . the capacitor?s voltage rating must exceed v dda . some typical values are shown in table 22. application c comp (nf) 8b/10b encoding, 1gbps, t on 1ms 10 sonet (62 b /64 b encoding), 1gbps 22 155mbps, t on 1ms 22 155mbps 100 table 22. typical values for c comp while there is no theoretical upper limit on the size of c comp , it is desirable for the loop to be able to track the changes resulting from periodic temperature compensation. the typical temperature compensation update period is 1.6s. therefore, a maximum size of 1mf is recommended. if laser turn-on time is not a factor, a value between 100nf and 1mf can be used for virtually any typical application. the tradeoff is that higher value capacitors have a larger physical size and cost. in order to maximize the power supply rejection ratio (psrr), c comp should be returned to gnda when the v bias output is sourcing current, e.g., driving an npn transistor (srce bit = 1). c comp should be returned to v dda when the v bias output is sinking current, e.g., driving a pnp transistor (srce bit =0). measuring laser bias current vild+ and vild? form a pair of pseudo-differential a/d inputs for measuring laser diode bias current via a sense resistor. the signal applied to these inputs is converted to a single-ended, ground-referenced signal for input into the adc and bias current fault comparator. these inputs have limited common-mode voltage range. the full-scale differential input range is v ref /4 or about 300mv. figure 26 and figure 27 illustrate the typical implementation of this function. note that vild? is always connected to the circuit?s reference potential: v dd in the case of a common-anode transmitter optical sub- assembly (tosa) and gnd in the case of a common- cathode tosa. note that the monitor photodiode current will also flow in the sense re sistor. this will result in a small offset in the measured bias current. the apc function will hold th is term constant, so it can be corrected for in the external calibration constants. the sensing resistor could also be connected between v dd and the emitter of q1 on figure 26 or between the emitter of q1 and gnd on figure 27. interfacing to laser drivers in order for the MIC3001 to control the modulation current of the laser diode, an interface circuit may be required depending on the method used by the driver to set its modulation current level. ge nerally, most laser diode driver ics use one of three methods: a) a current, i set , is sourced into a pin on the driver ic. the modulation current delivered by the driver is then some fixed multiple of i set . the sy88912 is an example of this type of driver. a simple circuit
micrel, inc. MIC3001 august 2004 71 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 can be used to create a current source controlled by the v mod outputs. the circuit is based on an external bipolar transistor and a current sensing resistor. b) a current, i set , is drawn out of a pin on the driver ic. the modulation current delivered by the driver is then some fixed multiple of i set . a simple circuit can be used to create a current source controlled by the v mod outputs. the circuit is based on an external bipolar transistor and a current sensing resistor. c) a voltage, v set , is applied to a pin on the driver ic. this voltage may be referenced to gnd or v dd . the MIC3001?s v mod+ output can supply this voltage directly. if a voltage swing wider than v ref is needed, gain can be applied with a pair of external resistors. the sy88932, sy88982, and sy89307 are examples of this type of driver. sy88912 3.3v 3.2gbps sonet/sdh laser driver the modulation level of the sy88912 driver is controlled by the current sourced into the rset pin (type (a) above). the circuit shown in figure 30.allows the MIC3001?s v mod outputs to control the sy88912?s modulation current from its minimum value, 5ma, to its maximum value, 60ma. the circuit operates as a dac-controlled current source. the current source is formed by the v mod buffer amplifier, external transistor, and current sense resistor. the op-amp acts to force the voltage drop across rset to be equal to the dac output voltage. the current, i set , through rset is therefore regulated as i set = v mod+/ r set (in this case, the dac output and therefore the op-amp output, are referenced to v dda .) the sy88912?s current gain, i mod /i set , is 23. a modulation current level of 60ma requires i set = 60ma/23 = 2.61ma; a modulation current level of 5ma requires i set = 5ma/23 = 0.217ma. r fltr and c fltr are optional and act to eliminate any noise that might be present on v dda or v mod . the values shown give a 100ms time constant. note that the time c onstant is present whenever the laser is turned on or turned off. this must be taken into account when designing to system specifications such as the sfp msa?s t on and t off requirements. the values of r fltr and/or c fltr may need to be adjusted accordingly. the impact of the filter time constant on the turn off time can be eliminated by using the MIC3001?s shdn signal to drive the sy88912?s enable input, /en. the use of the shdn signal is completely optional. the main benefit to using shdn, however, is that it shuts down the driver very quickly and irrespective of the values of r fltr and c fltr . the values of r fltr and c fltr can therefore be increased, enhancing their effect without incurring any turn-off time penalty. depending on the polarity chosen for shdn using the spol bit, an inversion may be required between the MIC3001?s shdn output and the driver?s /en input. (the shdn output may also be used to drive a redundant safety switch and the same polarity may not be appropriate for both functions.) figure 30. controlling the sy88912 modulation current for the circuit of figure 30, the modulation current control range and corresponding dac values are shown in table 23 below. dac v dda -v moc i set i mod 0 0v 0ma 0ma 19 0.091v 0.216ma 4.98ma 127 0.61v 1.45ma 33.4ma 255 1.22v 2.91ma 66.8ma table 23. control range of sy88912 modulation control circuit sy88932 3.3v 3.2gbps sonet/sdh laser driver the modulation level of the sy88932 driver is controlled by the voltage applied to the vctrl pin (type (c) above). the circuit shown in figure 31 allows the MIC3001?s v mod output to control the sy88932?s modulation current. the circuit operates as a dac- controlled voltage source. vctrl is simply the dac output voltage. see section above on sy88912 for r fltr , c fltr and shdn. figure 31. controlling the sy88932 modulation current
micrel, inc. MIC3001 august 2004 72 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 sy89307 5.0v/ 3.3v 2.5gbps vcsel driver the modulation level of the sy89307 driver is controlled by the voltage applied to the vctrl pin (type (c) above). the circuit shown in figure 32 allows the MIC3001?s v mod output to control the sy89307? s output swing. vctrl is simply the dac output voltage. the circuit operates as a dac-controlled voltage source. see section above on sy88912 for r fltr , c fltr . figure 32. controlling the sy89307 modulation current laser drivers programmed via a sink current the modulation level of some laser diode drivers is controlled by a current sourced out of the rset pin (type (b) above). the circuit shown in figure 33 allows the MIC3001?s v mod outputs to control the set current, iset. the circuit operates as a dac-controlled current sink. the current sink is formed by the v mod buffer amplifier, external transistor, and current sense resistor. the op-amp acts to force the voltage drop across rset to be equal to the dac output voltage. the current through r set is therefore regulated as i rset = v mod +/r set . i set is given by the equation: (13) where b is the dc gain of q1 the higher the gain of the transistor, the closer i set will be to the current in r set . r fltr and c fltr act to eliminate any noise that might be present on v dda or v mod . the values shown give a 100ms time constant. see section above on sy88912 for r fltr , c fltr and shdn. figure 33. controlling the modulation current via a sink current drivers with monitor outputs laser diode driver ics have been introduced with monitor outputs. these outputs provide ground-referred signals that mirror critical signals like laser bias current, modulation current or monitor photodiode current, an analog of transmitted power. generally, these outputs source a current into an external resistor to generate a ground-referenced voltage. using these outputs with the MIC3001 is straightfo rward since the MIC3001?s vild+/? and vmpd inputs are polarity programmable, shutdown output the shutdown output, shdn, can be used in two ways: as an enable or on/off control for the laser driver ic, and/or to control a redundant switch in the laser current path. the redundant switch provides a means for the MIC3001 to shut off the laser current even if the bias transistor or modulator is damaged or fails. shdn is active any time the MIC3001 shuts down the laser, i.e., if the txdisable function is asserted in hardware or software, or if the fault dete ction circuits trigger laser shutdown. the shutdown output, shdn, is essentially a logic output with programmable polarity. the programmable polarity allows shdn to drive either high-side or low-side switches or active-high or active- low enable inputs without the need for external inversion circuits. if an ac tive-low and an active-high shutdown signal are required, an external inverter will be necessary. examples of redundant switch circuits are shown in figure 34.
micrel, inc. MIC3001 august 2004 73 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 figure 34. redundant switch circuits temperature sensing the MIC3001 can measure and report its own internal temperature or the temperature of a remote pn junction or ?thermal diode?. in either case it is important to note that any board-mounted semiconductor device tends to track the ground plane temperature around it. the dominant thermal path to the sensor is often the ground pin. the ground pin usually connects to the lead-frame paddle on which the die is mounted. typical semiconductor packages, being non-conductive plastic, in sulate the device from the ambient air. the advantage to using a remote sensor is that the temperature may be sensed at a specific location, such as in the proximity of the laser diode, or away from any heat sources where it will more cl osely track the transceiver?s case temperature. the measur ed temperature is reported via the digital diagnostics regist ers and is used to index the temperature compensation tables. (note: sff-8472 does not specify the meaning of the reported temperature information or the location fr om which it is taken. this information is to be specified in the transceiver vendor?s datasheet.) remote sensing for remote temperature sensing using the xpn pin, most small-signal pnp transi stors with characteristics similar to the jedec 2n 3906 will perform well as thermal diodes. table 24 lists several examples of such parts that micrel has tested for use with the MIC3001. other transistors equivalent to these should also work well. vendor part number package fairchild semiconductor mmbt3906 sot-23 on semiconductor mmbt3906l sot-23 infineon technologies smbt3906/mmbt3906 sot-23 samsung semiconductor kst3906-tf sot-23 table 24. transistors suitable for use as remote diodes minimizing errors self-heating one concern when measuring temperature is to avoid errors induced by self-heating. self-heating is caused by power dissipation within the MIC3001. it is directly proportional to the internal power dissipation and the junction-to-ambient thermal resistance, ja . the dissipation in the MIC3001 must be calculated and reduced to a temperature offset. the power dissipation, pdiss, includes the effect of quiescent current and all currents flowing into or out of any signal pins, especially v bias and v mod . the temperature rise caused by self-heating is given by: (14) ja is given in the ?operating ratings? section above as 43c/w. the possible contributors to self-heating are listed in table 25. the numbers given in table 25 suggest that the power dissipation in a typi cal application will be no more than a few tens of milliwatts, leading to self- heating on the order of 1c.
micrel, inc. MIC3001 august 2004 74 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 table 25. contributors to self-heating in any application, the best and often easiest approach is to measure performance in the final application environment. this is especially true when dealing with systems for which some temperature data may be poorly defined or unobtainable except by empirical means. if desired, the external calibration constants may be used to correct the temperature readings. series resistance with external temperature sensor the operation of the mi c3001 depends upon sensing the vcb-e of a diode-connected pnp transistor (?diode?) at two different current levels. for remote temperature measurements, this is done using an external diode connected between xpn and ground. since this technique relies upon measuring the relatively small voltage difference resulting from two levels of current through the external diode, any resistance in series with the external diode will cause an error in the temperature reading from the MIC3001. a good rule of thumb is this: for each ohm in series with the external transistor , there will be a 0.9c error in the MIC3001?s temperature measurement. it is not difficult to keep the series resistance well below an ohm (typically <0.1), so th is will rarely be an issue. xpn filter capacitor selection it is desirable to employ a filter capacitor between xpn and gnda. the use of this capacitor is especially recommended in environments with a lot of high frequency noise (such as digital switching noise), or if long wires are used to connect to the remote diode. the maximum recommended total capacitance from the xpn pin to gnd is 2000pf. the recommended typical capacitor is a 1000pf np0 or c0g ceramic capacitor with a 10% tolerance. if the remote diode is to be at a distance of more than 6" to 12" from the MIC3001, using twisted pair wiring or shielded microphone cable for the connections to the diode can significantly reduce noise pickup. if using a long run of shielded cable, remember to subtract the cable?s conductor-to-shield capacitance from the 2000pf maximum total capacitance. xpn layout considerations the following guidelines should be kept in mind when designing and laying out circuits using the MIC3001 and a remote thermal diode: 1. place the MIC3001 as close to the remote diode as possible, while taking care to avoid severe noise sources such as high speed data busses, and the like. 2. since any conductance from the various voltages on the pc board and the xpn line can induce errors, it is good practice to guard the remote diode?s emitter trace with a pair of ground traces. these ground traces should be returned to the MIC3001?s own ground pin. they should not be grounded at any other part of their run. however, it is highly desirable to use these guard traces to carry the diode?s own ground return back to the ground pin of the MIC3001, thereby providing a kelvin connection for the base of the diode. 3. when using the MIC3001 to sense the temperature of a processor or other device which has an integral thermal diode, connect the emitter and base of the remote sensor to the MIC3001 using the guard traces and kelvin return shown in figure 35. the collector of the remote diode is typically inaccessible to the user on these devices. 4. due to the small currents involved in the description magnitude notes quiescent power i dd x v dd typically v dd = 3.3v, i dd = 2.7ma 3.3v x 2.7ma = 8.91mw. shdn current i ol x v ol negligible if mosfet is used as shutdown device. txfault current i ol x v ol worst case is v dd 2 /r pullup ; r pullup is 4.7k ? min. per sfp msa 3.3v 2 /4.7k ? = 2.32mw. v bias current v bias x i vbias or (v dd ?v bias ) x i vbias worst-case is v ref x 10ma = 1.22v x 10ma = 12.3mw. v mod current v mod x i vmod or (v dd ?v mod ) x i vmod worst-case is v ref x 10ma = 1.22v x 10ma = 12.3mw. rsout current i ol x v ol only for rate-agile applications using rsin/rsout. data current i ol x v ol x duty_cycle may be negligible; depends on bus speed, pull-up current, and bus activity. rxlos current i ol x v ol worst case is v dd 2 /r pullup ; r pullup is 4.7k ? min. per sfp msa 3.3v 2 /4.7k ? = 2.32mw.
micrel, inc. MIC3001 august 2004 75 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 measurement of the remote diode?s dvbe, it is important to adequately clean the pc board after soldering to prevent current leakage. this is most likely to show up as an issue in situations where water-soluble soldering fluxes are used. 5. in general, wider traces for the ground and t1 lines will help reduce susceptibility to radiated noise (wider traces are less inductive). use trace widths and spacing of 10 mils wherever possible and provide a ground plane under the MIC3001 and under the connections from the MIC3001 to the remote diode. this will help guard against stray noise pickup. figure 35. guard traces and kelvin return for remote thermal diode layout considerations small form-factor pluggable (sfp) transceivers the pinout of the MIC3001 digital control and status signals was optimized for use in small form-factor pluggable (sfp msp) optical transceivers. if the MIC3001 is mounted on the bottom of the pc board with the correct rotation, the control and status i/o can be routed to the host connector without changing the order. this is shown in figure 36. figure 36. typical sfp control and status i/o signal routing (not to scale) power supplies the MIC3001 has separate power supply and ground pins for both the analog and digital supplies. this helps prevent digital switching noise from corrupting the analog functions. the individual supply and ground pins are not isolated from one another inside the ic. separate analog and digital power and ground planes are not required on the pcb. having one of each plane (power and ground) is certainly good practice, however. if dedicated power and ground layers are not available, care should be taken to route the digital supply and return currents back to the supply separate from the analog supply connections. a schematic of this approach is shown in figure 37. each supply should be bypassed as close to the ic as possible with 0.01f capacitor (low esr capacitors such as ceramics are preferred.) as shown. this assumes that bulk capacitance is already present upstream. if no other filter capacitance is present nearby, a 1f filter capacitor should be added in parallel to the 0.01f capacitor. figure 37. power supply routing and bypassing using the MIC3001 in a 5v system it is fairly straightforw ard to use the MIC3001 in a system powered from a 5v ra il. in these systems, the laser diode driver ic will usually be powered from the 5v rail. a small linear regulator, such as micrel?s mic5213, can be used to generate a 3.3v power supply rail if one does not other wise exist in the system. all of the MIC3001?s digital i/o?s except for rsout are 5v tolerant and may be pulled up to 5.5v regardless of the MIC3001?s supply volta ge. they can be connected directly to a 5v host. the mic5213 is ideal, as it is capable of supplying up to 80ma, is in a tiny sc-70 package, and is stable with small ceramic output capacitors. the laser diode driver interface will be unchanged in most cases. ground referred voltages and currents can be generated the same way as with 3.3v-powerd drivers. the exception is driv ers that are controlled by a voltage referenced to v dd such as the sy89307. the MIC3001?s v bias or v mod output will be referenced to its own 3.3v power supply whereas the driver?s input will be referenced to its 5v power supply. the solution is a simple level-shifting circ uit that converts the v bias /v mod output into a current and then into a v dd -referenced voltage.
micrel, inc. MIC3001 august 2004 76 m9999-082404-a hbwhelp@micrel.com or (408) 955-1690 package information 24-pin mlf ? (mlf-24) micrel, inc. 2180 fortune drive san jose, ca 95131 usa tel +1 (408) 944-0800 fax +1 (408) 474-1000 web http:/www.micrel.com the information furnished by micrel in this data sheet is belie ved to be accurate and reliable. however, no responsibility is a ssumed by micrel for its use. micrel reserves the right to change circuitry and specificati ons at any time without notification to the customer. micrel products are not designed or authori zed for use as components in life support app liances, devices or systems where malfu nction of a product can reasonably be expected to result in personal injury. li fe support devices or systems are devices or systems that (a ) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to resul t in a significant injury to the user. a purchaser?s use or sale of micrel products for use in life s upport appliances, devices or systems is a pu rchaser?s own risk and purchaser agrees to fully indemnify micrel fo r any damages resulting from such use or sale. ? 2004 micrel , incor p orated.

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