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rev. 2d, 10/26/00. the information provided in this data sheet is preliminary and is subject to change without notice. pg. 1 of 14 conexant proprietary and confidential network access division data sheet CX60077 2.5 gbps long haul laser driver key features ? single supply : -5.2 volts ? cml interface (with capability of receiving ecl level) ? low power consumption 400 mw ? input impedance of 50 ? ? loss of input data detection ? pulse and bias current monitors ? 1 to 80 ma laser diode bias current ? 5 to 80 ma pulse current range applications ? fiber-optic communication systems (oc-48) ? sonet/sdh test equipment product description the CX60077 is a high-speed laser driver designed for use in a transmitter module for fiber-optic communications, such as synch ronous optical network (sonet), synchronous digital hierarchy (sdh), asynchronous transfer mode (atm), and dense wavelength division multiplexer (dwdm). this device can achieve a maximum output drive current of 80 ma into a 25 ? load. figure 1 illustrates the functional block diagram, and table 1 lists terminal descriptions. the CX60077 is available in a 32-pin flat pack, which is il lustrated in figures 10 and 11. figure 1. CX60077 functional block diagram datain clockin dutycntl ipcntl retimdis vbbsel ipoutp ipoutn ipmon pulse current driver retime ff loss of signal detect duty cycle cntlr vbb level select los 2:1 mux lostest dc bias current cntlr ibcntl ibmon ibout input buffers 50 ? 50 ? vttc vttd
2.5 gbps long haul laser driver rev. 2d, 10/26/00. the information provided in this data sheet is preliminary and is subject to change without notice. pg. 2 of 14 conexant proprietary and confidential table 1. CX60077 terminal descriptions number terminal name description type i/o rate/dc 27 ibout laser diode, dc bias current output current sink o dc 21 ibcntl dc bias current, control signal input analog i dc 22 ibmon dc bias current monitor current sink o dc 19 los loss of input or clock signal indicator output current sink dc 15 vbbsel vbb (threshold) voltage select between cml and ecl (1) dc 11 datain data input cml i 2.5 ghz* 17 retimdis input for disabling data and clock retiming (2) i dc 24 ibmon2 additional independent ibmon output current sink o dc 13 clkin clock input cml i 2.5 gbps* 16 lostest loss of signal test input (3) analog i dc 18 dutycntl output current, duty cycle control signal input analog i dc 3, 4, 5, 6, 25 vee supply voltage - - dc 20 ipcntl output current, control signal input analog i dc 23 ipmon output pulse current monitor current sink o ac 1, 2, 7, 8, 9, 10, 26, 30 gnd ground - dc 31, 32 ipoutn inverted output current sink o 2.5 gbps 28, 29 ipoutp non-inverted output current sink o 2.5 gbps 14 vttc 50 ? input clock termination reference ac ground i dc 12 vttd 50 ? input data termination reference ac ground i dc * high speed terminal note 1: see table 2. note 2: to select retimed data this terminal can be connected to -2 v or it can float. connecting the retimdis terminal to ground selects non-retimed data. note 3: this is an input to allow testing of the los function. when it is grounded: assert los output signal continuously. wh en it is connected to -2.0 v: enable los function. functional description the CX60077 2.5 ghz long haul laser driver translates input data on datain from a digital voltage signal to a digital current s ignal on pins ipoutp and ipoutn to drive a laser diode. the input buffers accept data, clock, and test signals and transfer the buffered sig nals to their respective circuits. when the input data and clock are direct coupled, the input threshold level is set by means of the vbbsel terminal. see table 2 for the relationship between vbbsel and the input threshold level. retimed data is selected with the retimdis terminal, and the duty cycle of the output signal is controlled with the dutycntl pi n. the data output pulse current driver ipout (p/n) is adjusted using the ipcntl pin and monitored using the ipmon pin. a current driver supplying dc bias for the laser is provided on pin ibout. the output bias current is monitored using the ibmon and/or ibmon2 p ins and adjusted using the ibcntl pin. the loss of signal (los) detect circuit detects the loss of transitions on the data signal. when a los is detected, the output of this circuit can be used to shut down both the output pulse (ip) current and dc bias current (ib). the lostest pin provides a means to simu late a los condition for testing.
2.5 gbps long haul laser driver rev. 2d, 10/26/00. the information provided in this data sheet is preliminary and is subject to change without notice. pg. 3 of 14 conexant proprietary and confidential high speed inputs and vbb level select the datain and clkin pins are high-speed cml data inputs each having a 50 ? on-chip termination resistor to vttd and vttc respectively (see figure 1) and are capable of operating at cml and ecl logic levels, as described in table 2. the vbbsel pin controls the threshold voltage for the lostest, datain, and clkin input buffers, as described in table 2. the v ttd and vttc pins should be connected to ground when the datain and clkin pins are direct coupled to a cml output. when the datain and clkin pins are direct coupled to an ecl output, the vttd and vttc pins should be connected to -2 v. when datain and clkin are ac cou pled, vttd and vttc should be connected to -0.45 v. the cml threshold is -0.45 v and the ecl threshold is -1.32 v. it is necessary to for the clock and data inputs to have an ed ge through these thresholds. for low input clock and/or data levels, it might be necessary to either ac couple and connect vttc and/or vt td to a negative voltage source to ensure there is an edge through the appropriate threshold. table 2. required connections datain/clkin input type v threshold vttc/vttd connection vbbsel connection cml direct coupled -0.45 ground open ecl direct coupled -1.32 -2.0 v ground ac coupled -0.45 -0.45 v open input data retiming input data from the datain pin is retimed in the retime flip-flop by a clock signal from the clkin pin. figure 2 illustrates t he datain and clkin relationship. figure 2. falling edge of clkin synchronized to data transitions datain t s t h 50% clkin t s , min. = t h , min. = 80 ps
2.5 gbps long haul laser driver rev. 2d, 10/26/00. the information provided in this data sheet is preliminary and is subject to change without notice. pg. 4 of 14 conexant proprietary and confidential retiming terminal a high-isolation 2:1-multiplexer (2:1 mux) selects retimed data from the retime flip flop when the retimdis pin is connected to an ecl logic high level (-2.0 v) or left open. the retimdis input is compatible with ecl logic levels, and has an on-chip 250 a current sink. setting retimdis to ground enables the 2:1 mux to select non-retimed data directly from the datain input buffer. duty cycle control the analog input voltage on the dutycntl pin controls the duty cycle of the data output (ipout). this input incorporates a 250 a current sink. the dutycntl pin should be connected to ground through an external resistor or controlled with a voltage source (i.e. a dac). by varying the resistor value, thus the input voltage, the CX60077 duty cycle can be modified. figure 3 illustrates the duty cycle as con trolled by the resistor value. figure 3. duty cycle and dutycntl voltage versus resistor value variation of duty cycle with external resistance 0 10 20 30 40 50 60 70 80 200 300 400 500 600 700 800 resistance ( ? ) dut ycy cle (%) min. max.
2.5 gbps long haul laser driver rev. 2d, 10/26/00. the information provided in this data sheet is preliminary and is subject to change without notice. pg. 5 of 14 conexant proprietary and confidential pulse current driver, control and monitoring the dual ipoutp and ipoutn pins (signal complements) are the CX60077 data output signals. each of the two ipoutp/n pins must b e terminated into 50 ? , or alternatively, two of the same phase pins can be connected together to drive a 25 ? load. the ipcntl pin, using an externally supplied current, controls the amplitude of the ipoutp/ipoutn pulse modulation current, which is approximately twent y times the ipcntl input current. the ipmon pin monitors the ipout modulation current. the ipmon pin sinks one-twentieth of the ipout modulation current in the high state and will be equal to ipcntl. figure 4 illustrates the ip control characteristics. figure 4. ip control characteristics output pulse current (ipoutp/n) ipcntl (ma) 0.25 4.0 80 ma 5.0 ma 2.0 40 ma ipmonp, ipmonn current (ma) 4.0 2.0 0.25 + 5.0 % - 5.0 % dc bias current driver, control and monitoring the ibout pin provides an adjustable dc bias current for use with the laser diode. the ibcntl pin, using an externally supplie d current, controls the dc bias current on ibout. the dc bias current on ibout will be approximately twenty times the ibcntl input current. the ibmon and ibmon2 pins are separa te but identical outputs, which monitor the ibout current and are capable of sinking one-twentieth of the ibout current. figure 5 ill ustrates the ib control characteristics. figure 5. ib control characteristics ibcntl (ma) 0.25 4.0 80.0 ma 1.0 ma 2.0 40.0 ma ib bias current (ibout) 4.0 ma 2.0 ma 0.05 ma ib bias monitor (ibmon) + 5.0 % - 5.0 %
2.5 gbps long haul laser driver rev. 2d, 10/26/00. the information provided in this data sheet is preliminary and is subject to change without notice. pg. 6 of 14 conexant proprietary and confidential loss of signal detection the loss of signal (los) detect circuit detects the loss of transitions in the data path out of the 2:1 mux. under normal oper ating conditions when data is toggling los remains high (gnd). when data is lost (no signal transitions) the los output pin goes low (-2.0 v). figure 6 illustrates the los detect circuit timing waveforms. los can be used by an external control circuit to shut down both the output pulse current and dc bias current drivers. los can be made cml logic compatible by termination with a 2 k ? resistor to ground for a los condition. the lostest input pin can be used to force los to assert (-2.0 v). this function is used for board test purposes. the lostest input is similar to the datain and clkin pins in that it is capable of handling either cml or ecl logic levels. however, lostest does n ot have an on-chip termination resistor. under normal operating conditions, whether using cml or ecl input levels, lostest should be held in the low (inactive) level (-2.0 v), or if lostest will not be used in board level tests, it should be terminated with a 2 k ? resistor into -2 v. figure 6. timing waveforms for the loss of data detect circuit with signal: locked no signal: unlocked data or clock signals los l h v h v l activation: 1.0 sec < ? t < 10.0 sec ? t t release: 1.0 sec < ? t < 10.0 sec <1.0 sec <1.0 sec with signal: locked ?
2.5 gbps long haul laser driver rev. 2d, 10/26/00. the information provided in this data sheet is preliminary and is subject to change without notice. pg. 7 of 14 conexant proprietary and confidential electrical specifications table 3 lists the CX60077 electrical specifications. table 3. CX60077 electrical specifications ts = 0 c to +85 c, vee = -5.2 v 10%, r l = 25 ? description parameter min typical max unit input data level (datain) (1) (2) vdat p-p 200 ? 1200 mv input clock level (clkin) (1) (2) vclk p-p 200 ? 1200 mv datain dc offset range mv clkin dc offset range mv input data duty cycle tdatdc 90 100 110 % input clk duty cycle tclkdc 45 50 55 % input data rise/fall time (3) tdatr, tdatf ? 110 140 psec input clk rise/fall time (3) tclkr, tclkf ? 75 90 psec bias current ib 1 ? 80 ma peak current ip 5 ? 80 ma output swing (peak-to-peak) v p-p ? ? 2.8 v output duty cycle (4) tipdc 84 100 116 % output rise/fall time tipr, tipf ? 90 130 ps power consumption (5) p ? 370 400 mw ipcntl versus ipout, ipmon ipcntl vs. ipout [(ipout) (ipcntl 20)] 0.9 1.00 1.10 ? ipcntl vs. ipmon [(ipmon) (ipcntl)] 0.95 1.00 1.05 ? ipout vs. ipmon [(ipout) (ipmon 20)] 0.987 1.00 1.012 ? ibcntl versus ibout, ibmon ibcntl vs. ibout [(ibout) (ibcntl 20)] 0.95 1.00 1.05 ? ibcntl vs. ibmon [(ibmon) (ibcntl)] 0.95 1.00 1.05 ? ibout vs. ibmon [(ibout) (ibmon 20)] 0.987 1.00 1.012 ? loss of signal detection characteristics (conditions) (see figure 6) los v l (los output low level) (no transitions on datain/clkin) v l-los -1.15 ? -0.85 v los v h (los output high level) (datain/clkin transitioning) v h-los -0.1 ? +0.1 v los activation time (no transitions on datain/clkin) t activation 1.0 ? 10 s los deactivation time (datain / clkin transitioning) t release 1.0 ? 10 s notes: (1) input value: 0.900 v p-p. (2) it is necessary to have a data and clock edge through the input threshold established by vbbsel: vbbsel = 0, input threshold = ecl = -1.32 v; vbbsel = open, input threshold = cml = -0.45 v. (3) based on 20%/80% levels. (4) duty cycle ratio = ?duty?/average data (nrz) bit period? (see figure 8). (5) outputs open.
2.5 gbps long haul laser driver rev. 2d, 10/26/00. the information provided in this data sheet is preliminary and is subject to change without notice. pg. 8 of 14 conexant proprietary and confidential table 4 lists the absolute maximum ratings. table 4. CX60077 absolute maximum ratings exceeding the CX60077 absolute maximum ratings listed in table 4 will damage the unit. parameter symbol min. max. unit supply voltage vee -7.0 +0.5 v input voltage vin vee -0.5 +0.5 v input current (datain, clkin) iin ? 50 ma input current (except datain, clkin) iin ? 8 ma ib, ib maximum current imax ? 120 ma case operating temperature tc -65 +150 c storage temperature tst -65 +150 c ? >2000 v electrostatic discharge (human body model) high-speed terminals esd ? 100 v table 5 lists the recommended operating conditions. table 5. CX60077 recommended operating conditions parameter symbol min typical max unit supply voltage vee -4.68 -5.20 -5.72 v operating temperature tc (1) 0 +25 +85 c junction temperature tj (1) 0 ? +150 c note 1: see figure 7 for locations for temperature measurement locations. figure 7. temperature measurement locations tj die tc heat slug package lead package body
2.5 gbps long haul laser driver rev. 2d, 10/26/00. the information provided in this data sheet is preliminary and is subject to change without notice. pg. 9 of 14 conexant proprietary and confidential waveform evaluation figure 8 illustrates the evaluation equivalent load circuit and waveform specifications. figure 8. equivalent load circuit for waveform evaluation (a) and waveform specifications (b) undershoot 100 % 80 % 50 % 20 % 0.0 ma t f overshoot duty t r (b) (a) laser diode r l laser diode driver ipout ipout specified by current waveform
2.5 gbps long haul laser driver rev. 2d, 10/26/00. the information provided in this data sheet is preliminary and is subject to change without notice. pg. 10 of 14 conexant proprietary and confidential typical application figure 9 is a block diagram of the CX60077 in a typical application. figure 9. CX60077 typical application block diagram datain clkin vee customer provided control circuitry CX60077 ipoutn ipoutn ipout ipout ibout ipmon ibmon ipcntl ibcntl los shutdown control circuitry 2k ? vttd vttc gnd los test dutycont clkdis vbbsel 2k ? 500 ? 50 ? 50 ? 25 ? v v -2.0 v
2.5 gbps long haul laser driver rev. 2d, 10/26/00. the information provided in this data sheet is preliminary and is subject to change without notice. pg. 11 of 14 conexant proprietary and confidential package pin configuration and assignments the CX60077 package pin configuration is illustrated in figure 10 and package pin assignments are listed in table 6. figure 10. package pin configuration pin 1 pin 17 pin 25 pin 26 pin 32 pin 16 pin 10 pin 9 table 6. package pin assignments pin number signal on pin 11 datain 12 vttd 13 clkin 14 vttc 15 vbbsel 16 lostest 17 retimdis 18 dutycont 19 los 20 ipcntl 21 ibcntl 22 ibmon 23 ipmon 24 ibmon2 27 ibout 28,29 ipoutp 31,32 ipoutn 1,2,7,8,9,10,26,30 gnd 3,4,5,6,25 vee
2.5 gbps long haul laser driver rev. 2d, 10/26/00. the information provided in this data sheet is preliminary and is subject to change without notice. pg. 12 of 14 conexant proprietary and confidential package dimensions figure 11 illustrates the CX60077 package dimensions in millimeters. figure 11. package pin configuration
2.5 gbps long haul laser driver rev. 2d, 10/26/00. the information provided in this data sheet is preliminary and is subject to change without notice. pg. 13 of 14 conexant proprietary and confidential ordering information name number package data 2.5 gbps long haul laser driver CX60077 30 pin flat pack revision history revision date comments CX60077 rev 2c 5/10/00 added review material. CX60077 rev 2d 10/26/00 adding engineering design changes. revised figure 2 and table 2. ? 2000, conexant systems, inc. all rights reserved. information in this document is provided in connection with conexant systems, inc. ("conexant") products. these materials are p rovided by conexant as a service to its customers and may be used for informational purposes only. conexant assumes no responsibility for errors or omissions in these materials. conexant may make changes to specifications and product descriptions at any time, without notice. conexant makes no commitment to update the information contained herein. conexant shall have no responsibility whatsoever for conflicts or incompatibilities ar ising from future changes to its specifications and product descriptions. no license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted by this document. exce pt as provided in conexant?s terms and conditions of sale for such products, conexant assumes no liability whatsoever. these materials are provided "as is" without warranty of any kind, either express or implied, relating to sale and/or use of conexant products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right. conexant further does not warrant the accuracy or completeness of the information, text, graphics or other items contained with in these materials. conexant shall not be liable for any special, indirect, incidental, or consequential damages, including without limitation, los t revenues or lost profits, which may result from the use of these materials. conexant products are not intended for use in medical, life saving or life sustaining applications. conexant customers using or selling conexant products for use in such applications do so at their own risk and agree to fully indemnify conexant for any damages resulting f rom such improper use or sale. the following are trademarks of conexant systems, inc.: conexant, the conexant c symbol, and ?what?s next in communications tec hnologies.? product names or services listed in this publication are for identification purposes only, and may be trademarks of third parti es. third-party brands and names are the property of their respective owners. reader response: conexant strives to produce quality documentation and welcomes your feedback. please send comments and suggest ions to conexant. tech.pubs@conexant.com . for technical questions, contact your local conexant sales office or field applications engineer.
2.5 gbps long haul laser driver rev. 2d, 10/26/00. the information provided in this data sheet is preliminary and is subject to change without notice. pg. 14 of 14 conexant proprietary and confidential further information: literature@conexant.com (800) 854-8099 (north america) (949) 483-6996 (international) world headquarters conexant systems, inc. 4311 jamboree road newport beach, ca 92660-3007 phone: (949) 483-4600 fax 1: (949) 483-4078 fax 2: (949) 483-4391 americas u.s. northwest/ pacific northwest ? santa clara phone: (408) 249-9696 fax: (408) 249-7113 u.s. southwest ? los angeles phone: (805) 376-0559 fax: (805) 376-8180 u.s. southwest ? orange county phone: (949) 483-9119 fax: (949) 483-9090 u.s. southwest ? san diego phone: (858) 713-3374 fax: (858) 713-4001 u.s. north central ? illinois phone: (630) 773-3454 fax: (630) 773-3907 u.s. south central ? texas phone: (972) 733-0723 fax: (972) 407-0639 u.s. northeast ? massachusetts phone: (978) 367-3200 fax: (978) 256-6868 u.s. southeast ? north carolina phone: (919) 858-9110 fax: (919) 858-8669 u.s. southeast ?florida & south america phone: (727) 799-8406 fax: (727) 799-8306 u.s. mid-atlantic ? pennsylvania phone: (215) 244-6784 fax: (215) 244-9292 canada ? ontario phone: (613) 271-2358 fax: (613) 271-2359 europe europe central ? germany phone: +49 89 829-1320 fax: +49 89 834-2734 europe north ? england phone: +44 1344 486444 fax: +44 1344 486555 europe ? israel/greece phone: +972 9 9524000 fax: +972 9 9573732 europe south ? france phone: +33 1 41 44 36 51 fax: +33 1 41 44 36 90 europe mediterranean ? italy phone: +39 02 93179911 fax: +39 02 93179913 europe ? sweden phone: +46 (0) 8 5091 4319 fax: +46 (0) 8 590 041 10 europe ? finland phone: +358 (0) 9 85 666 435 fax: +358 (0) 9 85 666 220 asia ? pacific taiwan phone: (886-2) 2-720-0282 fax: (886-2) 2-757-6760 australia phone: (61-2) 9869 4088 fax: (61-2) 9869 4077 china ? central phone: 86-21-6361-2515 fax: 86-21-6361-2516 china ? south phone: (852) 2 827-0181 fax: (852) 2 827-6488 china ? south (satellite) phone: (86) 755-5182495 china ? north phone: (86-10) 8529-9777 fax: (86-10) 8529-9778 india phone: (91-11) 692-4789 fax: (91-11) 692-4712 korea phone: (82-2) 565-2880 fax: (82-2) 565-1440 korea (satellite) phone: (82-53) 745-2880 fax: (82-53) 745-1440 singapore phone: (65) 737 7355 fax: (65) 737 9077 japan phone: (81-3) 5371 1520 fax: (81-3) 5371 1501 www.con exant.com

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