? semiconductor components industries, llc, 2006 january, 2006 ? rev. 3 1 publication order number: mc10sx1130/d mc10sx1130 led driver description the mc10sx1130 is high speed led driver/current switch specifically targeted for use in fddi pmd and ansi x3t9.3 fibrechannel 266 mbits/s optical transmitters. the integrated circuit contains several unique functional blocks which makes it easily configurable for use with a variety of high performance led devices. the part is fabricated using mosaic iii ? bipolar process. the logic is designed so that a data high input results in the modulation current flowing through the i out pin to turn on the led. the device incorporates open collector outputs with a capability of driving peak currents of 100 ma. since the output current switching circuitry simply switches current between the complementary outputs, the dynamic switching demands on the system power supply are greatly reduced. in addition, because the design is pure bipolar, the device current drain is insensitive to the data pattern and frequency of operation. the led drive current is adjustable through the selection of an external set resistor, rset. in addition, to allow for open loop compensation for the led?s negative optical output power tracking over temperature, a circuit is included to provide an adjustable positive temperature tracking coefficient to the led drive current. this is controlled through the selection of an external resistor, rtco. the mc10sx1130 incorporates novel pulse stretching circuitry which is intended to compensate for the turn-on delay and rise and fall time asymmetry inherent in led devices. the stretch circuitry can be used to pre-distort the input signal pulse width to minimize the duty cycle distortion of the transmitted optical eye pattern. the stretch circuitry supports three different selections of pre-distortion. this choice is accomplished through a unique ?tri-state? input which can be left open, tied to v cc , or tied to v ee to determine the pre-distortion amount. the device provides a v bb output for either single-ended use or as a dc bias for ac coupling the signal into the device. the v bb pin should only be used as a bias for the mc10sx1130 as its current sink/source capability is limited. whenever used, the v bb pin should be bypassed to ground via a 0.01 f capacitor. features ? differential data inputs ? 300 mhz operation ? 100 ma peak drive current ? extremely low jitter ? duty cycle distortion compensation ? adjustable output current tracking with temperature ? thermally enhanced 16-lead soic package ? 75 k data input pulldown resistors ? +5 v or ? 5.2 v operation ? v bb reference available ? pb ? free packages are available* *for additional information on our pb ? free strategy and soldering details, please download the on semiconductor soldering and mounting techniques reference manual, solderrm/d. led driver soic ? 16 d suffix case 751b http://onsemi.com marking diagram a = assembly location wl = wafer lot y = year ww = work week g= pb ? free package see detailed ordering and shipping information in the package dimensions section on page 8 of this data sheet. ordering information 10sx1130g awlyww
mc10sx1130 http://onsemi.com 2 15 16 14 13 12 11 10 2 1 34567 v ee 9 8 stretch v ee i out rset i out v cc v ee v ee v cc v bb d in d in rtco 1 rtco 2 v ee figure 1. pinout: soic ? 16 (top view) pulse width adjust circuit bias control rset rtco 1 rtco 2 i out i out stretch v bb d in d in ecl buffer figure 2. block diagram table 1. pin function table pin function d in differential data inputs. i out differential open collector outputs. stretch control input to select the amount of duty cycle pre-distortion. when the pin is left open, no pre-distortion is introduced. if the pin is connected to v cc , the output low state current pulse width is increased by 155 ps. when it is connected to v ee , the current pulse width is increased by 310 ps. rset resistor to set led drive current. this resistor sets the tail current of the output current switch and should be con- nected to the v ee plane. since the rset voltage compensation circuit is referenced to v ee , the rset voltage will track 1:1 with v ee changes, thus the voltage across the rset resistor will remain constant. rtco 1 , rtco 2 terminals for positive temperature tracking resistor. this resistor controls the temperature tracking rate of the voltage at the rset pin, which in turn sets the led drive current tracking. if the two pins are shorted together, the nominal tracking rate is 1.4mv/ c and when a 2 k resistor is connected across the pins, the nominal tracking rate is 4.9 mv/ c. v cc most positive power supply input. +5 v for pecl operation or ground for standard ecl operation. v ee most negative power supply input. ground for pecl operation or ? 5.2 v for standard ecl operation. v bb reference voltage for use in single ended applications or when the input signal is ac coupled into the device.
mc10sx1130 http://onsemi.com 3 figure 3. typical +5 v applications circuit 15 16 14 13 12 11 10 2 1 34567 v ee 9 8 stretch v ee i out rset i out v cc v ee v ee v cc v bb d in d in rtco 1 rtco 2 v ee 1 k 50 in pecl bias 50 in pecl bias 10 10 +5.0 v supply decoupling capacitors table 2. absolute maximum ratings symbol parameter value unit v ee power supply (v cc = 0 v) ? 7.0 to 0 vdc v i input voltage (v cc = 0 v) 0 to ? 6.0 vdc i out output current continuous surge 100 110 ma t a operating temperature range ? 40 to +85 c v ee operating range (v cc = 0) ? 5.5 to ? 4.5 vdc maximum ratings are those values beyond which device damage can occur. maximum ratings applied to the device are individual str ess limit values (not normal operating conditions) and are not valid simultaneously. if these limits are exceeded, device functional operation i s not implied, damage may occur and reliability may be affected.
mc10sx1130 http://onsemi.com 4 table 3. dc characteristics (rtco = 1 k 5%, r set = r at i out = r at i out = 10 1%, unless otherwise noted)(note 1) symbol characteristic -40 c 0 c 25 c 85 c unit min typ max min typ max min typ max min typ max i ih input high current (din, din pins) 200 200 200 200 a i il input low current (din, din pins) 0.5 0.5 0.5 0.5 a i cc quiescent supply current (no load on rset pin) 12 17 24 12 17 24 12 18 24 12 19 24 ma v ih input high voltage (note 2) v cc = 5.0v, v ee = gnd v cc = gnd, v ee = -4.5 to -5.5v 3770 -1230 4110 -890 3830 -1170 4160 -840 3870 -1130 4190 -810 3940 -1060 4280 -720 mv v il input low voltage (note 2) v cc = 5.0v, v ee = gnd v cc = gnd, v ee = -4.5 to -5.5 v 3050 -1950 3500 -1500 3050 -1950 3520 -1480 3050 -1950 3520 -1480 3050 -1950 3555 -1445 mv v bb output reference voltage (note 2) v cc = 5.0 v, v ee = gnd v cc = gnd, v ee = -4.5 to -5.5 v 3570 -1430 3700 -1300 3620 -1380 3730 -1270 3650 -1350 3750 -1250 3690 -1310 3810 -1190 mv v set output voltage at rset pin v cc = 5.0 v rtco = short v ee = gnd rtco = 1 k rtco = 2 k 600 430 230 635 515 355 610 570 470 690 650 550 770 730 630 775 855 845 mv v cc = gnd (note 3) rtco = short v ee = ? 5.2 v rtco = 1 k rtco = 2 k -4400 -4570 -4770 -4365 -4485 -4645 -4390 -4430 -4530 -4310 -4350 -4450 -4230 -4270 -4370 -4225 -4145 -4155 io on output ?on? current (iout, iout pins) 30 75 30 75 30 75 30 100 ma io off output ?off? current (iout, iout pins) 50 50 50 50 a v tr v set tracking (note 4) short between rtco1 and rtco2 1 k between rtco1 and rtco2 2 k between rtco1 and rtco2 1.4 3.4 4.9 1.4 3.4 4.9 1.4 3.4 4.9 1.4 3.4 4.9 mv/ c note: device will meet the specifications after thermal equilibrium has been established when mounted in a test socket or printe d circuit board with maintained transverse airflow greater than 500 lfpm. electrical parameters are guaranteed only over the declared operating temperature range. functional operation of the device exceeding these conditions is not implied. device specification limit values are applied individually under normal operating conditions and not valid simultaneously. 1. 10sx circuits are designed to meet the dc specifications shown in the table after thermal equilibrium has been established. t he circuit is mounted in a test socket or mounted on a printed circuit board and transverse air greater than 500 lfm is maintained. 2. note that in pecl applications, v ih , v il , v bb will vary 1:1 with the v cc supply. 3. v set tracks 1:1 with the v ee supply to maintain the same voltage across the rset resistor. 4. v tr tracking measures the rate of change of the v set voltage over temperature.
mc10sx1130 http://onsemi.com 5 table 4. ac characteristics (rtco = 1 k 5%, r set = r at i out = r at i out = 10 1%, unless otherwise noted) (note 5) symbol characteristic ? 40 c 0 to 85 c unit condition min typ max min typ max t plh , t phl propagation delay (differential) to output (single ? ended) 1300 1300 1000 950 1400 1400 1800 1850 ns t stretch propagation delay stretch = open stretch = v cc stretch = v ee (note 6) 0 145 300 120 250 0 155 310 200 380 ps t r 10 ? 90 t f 90 ? 10 rise time fall time 10% to 90% 90% to 10% 600 375 510 330 880 550 1260 860 ps t r 20 ? 80 t f 80 ? 20 rise time fall time 20% to 80% 80% to 20% 490 260 360 220 600 500 850 750 ps jitter jitter square wave input pseudo random input (note 7) (note 8) 9 10 6 15 ps bw bandwidth 300 400 300 400 mhz t skew duty cycle skew (differential) (note 9) 30 30 ps v pp minimum input swing (note 10) 150 150 mv v cmr common mode range (note 11) ? 0.400 see 7 ? 0.400 see 7 v note: device will meet the specifications after thermal equilibrium has been established when mounted in a test socket or printe d circuit board with maintained transverse airflow greater than 500 lfpm. electrical parameters are guaranteed only over the declared operating temperature range. functional operation of the device exceeding these conditions is not implied. device specification limit values are applied individually under normal operating conditions and not valid simultaneously. 5. 10sx circuits are designed to meet the ac specifications shown in the table after thermal equilibrium has been established. t he circuit is mounted in a test socket or mounted on a printed circuit board and transverse air greater than 500 lfm is maintained. 6. when the stretch function is used, the output low pulse width is increased by the specified amount. 7. test condition uses a 133 mhz 50% duty cycle signal. 8. test condition uses a 266 mbit/s input pseudo-random data stream (n = 23). 9. duty cycle skew is the difference between t plh and t phl propagation delay through a device, stretch input is left open. 10. minimum input swing for which ac parameters are guaranteed. 11. the cmr range is referenced to the most positive side of the differential input signal. normal operation is obtained if the high level falls within the specified range and the peak-to-peak voltage lies between v pp min and 1.0 v. the lower end of the cmr range is dependent on v ee and is equal to v ee + 3.5 v.
mc10sx1130 http://onsemi.com 6 applications information introduction the mc10sx1130 is intended to be integrated into high performance fiber optic modules or used stand-alone to drive a packaged optical led device. the wide frequency response of the device allows it to be used to support a variety of digital communication applications ranging from: ? oc1/3 sonet/sdh links ? 100 mbit/s fddi ? 155 mbit/s atm ? 133/266 mbit/s fibrechannel to support such wide ranging application areas, the led driver incorporates a variety of unique features. these offer designers added flexibility that could not previously be realized in less integrated designs. led characteristics led devices emit light when forward biased. the optical power emitted by an led is determined by the amount of current flowing through the device. this relationship is a relatively linear function of the current, until the device saturates. in some ways, an led device behaves much like a traditional small signal silicon diode, although the forward ?on? voltage of an led is much larger and ranges from 1.0 v to 2.0 v. in addition, for a fixed amount of current, the optical power from the led will decrease if the device junction temperature increases. another behavior of most led devices is that they have unequal turn-on and turn-off times. in developing an led transmitter, the designer must wrestle with all these behaviors to develop a product that meets the design targets. led driver the mc10sx1130 led driver accepts a digital binary data stream which is processed by the driver circuitry to create a current waveform to modulate the led device. the led driver contains circuitry to program the modulation current, pre-distort the input waveform to partially compensate for the led turn-on/turn-off delay, and compensate for the negative optical output power tracking co-efficient. the led driver operates from a +5 v supply for pecl applications or a ? 5.2 v supply for traditional ecl systems. for further information on pecl, please consult ?designing with pecl application note?, an1406/d available from a on semiconductor representative. circuit blocks some of the key sub-circuits in the led driver are listed below: ? input line receiver ? pulse stretcher ? bias control circuitry ? output current switch the data input circuitry has been realized as a traditional differential ecl line receiver. it can accept either differential 100k or 10kh style ecl or pecl depending on the supply voltage used. in addition, a v bb reference is provided for use in single ended applications. this reference is useful if the input signal must be ac coupled into the device. the pulse stretcher provides two choices of duty cycle pre-distortion. it is controlled by the input stretch signal. when the pin is left open, no pre-distortion is applied to the input waveform. if the pin is strapped to the upper or lower rail, then the output waveform low pulse width will be increased. in a +5 v application, when the stretch pin is tied to +5 v, the nominal pulse width increase is 155 ps and when it is connected to 0 v, the nominal pulse width is increased by 310 ps. the bias control circuitry regulates the voltage supplied at the rset pin of the output current switch. in addition, it implements a positive tracking circuit which provides open loop temperature compensation for the led?s negative tracking coef ficient. an external resistor connected between the rtco 1 and rtco 2 is used to select the rate of voltage change at the rset pin. the output current switch is the final stage in modulating the led. the emitter of the current source is pinned out so that an external resistor can be used to set the modulation current. this circuit is implemented using a fully dif ferential gate where both collectors are brought out. as the led is modulated on and off, the current switches from one collector to another. this architecture minimizes the switching noise inherent in some led driver design topologies where the modulation current is actually turned on and off. design considerations once the user has selected an led, the driver circuitry should be optimized to match the characteristics of the led. the three circuit blocks previously described allow the user to control the pulse width adjustment, led drive current and temperature tracking rate. a very simple example may best illustrate the design process steps. an led has been selected which has the desired optical output power when modulated with a waveform of 65ma. in addition, the led has an output power tracking coefficient of ? 0.5%/ c. thus for every 1 c rise in the case temperature of the led, the output power will decrease by 0.5% of the nominal value. in addition, the led forward voltage is 1.5 v.
mc10sx1130 http://onsemi.com 7 first, the rset resistor must be chosen to set the desired nominal modulation current based on the following equation: rset = v set /i mod (equation 1) the voltage at vset is a function of the rtco tracking resistor, so the desired tracking rate (vtr) must also be chosen. to determine this, the equation must be normalized to correspond to how the led has been specified. temp co = v tr /v set (equation 2) the data sheet has three temperature tracking rates for different values of the rtco resistor. by using the v set values at 25 c and substituting those numbers into equation 2, normalized tracking rates can be calculated. table 5. normalized tracking at 25 c rtco tracking %/ c short +0.20 1 k +0.52 2 k +0.89 to match the led chosen, a 1 k resistor can be used. now that this is known, the value of the voltage at the v set can be substituted into equation 1 to determine the value of rset resistor which, for this example is 10 . the stretch circuit can be used to compensate for the turn-on/turn-off delay of the led. the circuit has been designed for ease of use so the pin is designed to be strapped to one of the two power plane levels to select the pre-distortion value. if no pre-distortion is desired, the pin can be left open. in this +5 v example, the maximum amount of pre-distortion is desired, so the stretch pin is connected to ground. in addition a resistor must be placed between i out and v cc . in selecting this resistor, just as in the case of the rset, the resistor type should be chosen to dissipate the worst case power and derated for the worst case temperature. as a rule of thumb, the voltage drop across the resistor should match the forward voltage across the diode. the voltage can be larger to minimize the power dissipated on chip when the led is not ?on?. although, the voltage drop across this resistor should not be greater than 2 v. for this example: r @ i out = vf/i mod i mod(max) v set @85 c rset 855mv 10 86ma r @ i out = 1.5v/86ma = 17 because of the positive tracking circuitry in the led driver, the modulation current will increase over temperature. it is important to now go back and re-calculate the numbers under the worst case environmental conditions to ensure that operating conditions have not been exceeded. thermal management led devices tend to require large amounts of current for most ef ficient operation. this requirement is then translated into the design of the led driver. when large modulation currents are required, power dissipation becomes a critical issue and the user must be concerned about the junction temperature of the device. the following equation can be used to estimate the junction temperature of a device in a given environment: t j = t a + p d * ja (equation 3) t j junction temperature t a ambient temperature p d power dissipation ja average thermal resistance (junction-ambient) a specially designed thermally enhanced leadframe has been used to house the led driver. below is a graph of the average ja plotted against air flow. figure 4. typical ja versus airflow 70 80 90 100 110 0 100 200 300 400 500 airflow (lfpm) ja ( c/w) the power dissipation of the device has two components; the quiescent power drain related to the pre-drive circuitry, and the power dissipated in the current switch when driving the led. pd = pstatic + pswitching (equation 4) the power dissipated in the current switch is a function of the imod current, the led forward voltage, and the value of rset. for example in a +5 v application, the following equations can be used: pstatic = v cc * i cc (equation 5) pswitching = (v cc -v f -v set )* i mod (equation 6)
mc10sx1130 http://onsemi.com 8 now to calculate the dissipated power on the chip for a nominal application. v cc = 5 v v f = 1.5 v v set = 0.7 v i mod = 60 ma i cc = 18 ma so: pd = 5 * 18 + (5 - 1.5 - 0.7) * 60 pd = 258 mw this number can be entered into equation 3 along with the environmental information to calculate the nominal operating junction temperature. because of the open loop feedback control in the bias control circuitry, the revised i mod value must be determined given the tracking rate chosen so that the power dissipation can be re-calculated. for assessing product reliability, worst case values should be entered to calculate the maximum junction temperature. reliability of plastic packages although today?s plastic packages are as reliable as ceramic packages under most environmental conditions, as the junction temperature increases a failure mode unique to plastic packages becomes a significant factor in the long term reliability of the device. modern plastic package assembly utilizes gold wire bonded to aluminum bonding pads throughout the electronics industry. as the temperature of the silicon (junction temperature) increases, an intermetallic compound forms between the gold and aluminum interface. this intermetallic formation results in a significant increase in the impedance of the wire bond and can lead to performance failure of the affected pin. with this relationship between intermetallic formation and junction temperature established, it is incumbent on the designer to ensure that the junction temperature for which a device will operate is consistent with the long term reliability goals of the system. reliability studies were performed at elevated ambient temperatures (125 c) from which an arrhenius equation, relating junction temperature to bond failure, was established. the application of this equation yields the table of table 6. this table relates the junction temperature of a device in a plastic package to the continuous operating time before 0.1% bond failure (1 failure per 1000 bonds) the mc10sx1130 device is designed with chip power levels that permit acceptable reliability levels, in most systems, under the conventional 500 lfpm (2.5 m/s) airflow. t = 6.376 10 ? 9 e 11554.267 273.15 + t j where: t = time to 0.1% bond failure table 6. t j vs time to 0.1% bond failure junction temp. ( c) time (hrs.) time (yrs.) 80 1,032,200 117.8 90 419,300 47.9 100 178,700 20.4 110 79,600 9.1 120 37,000 4.2 130 17,800 2.0 140 8,900 1.0 ordering information device package shipping ? mc10sx1130d soic ? 16 48 units / rail mc10sx1130dg soic ? 16 (pb ? free) 48 units / rail mc10sx1130dr2 soic ? 16 2500 / tape & reel MC10SX1130DR2G soic ? 16 (pb ? free) 2500 / tape & reel ?for information on tape and reel specifications, including part orientation and tape sizes, please refer to our tape and reel packaging specifications brochure, brd8011/d.
mc10sx1130 http://onsemi.com 9 package dimensions soic ? 16 d suffix case 751b ? 05 issue j notes: 1. dimensioning and tolerancing per ansi y14.5m, 1982. 2. controlling dimension: millimeter. 3. dimensions a and b do not include mold protrusion. 4. maximum mold protrusion 0.15 (0.006) per side. 5. dimension d does not include dambar protrusion. allowable dambar protrusion shall be 0.127 (0.005) total in excess of the d dimension at maximum material condition. 18 16 9 seating plane f j m r x 45 g 8 pl p ? b ? ? a ? m 0.25 (0.010) b s ? t ? d k c 16 pl s b m 0.25 (0.010) a s t dim min max min max inches millimeters a 9.80 10.00 0.386 0.393 b 3.80 4.00 0.150 0.157 c 1.35 1.75 0.054 0.068 d 0.35 0.49 0.014 0.019 f 0.40 1.25 0.016 0.049 g 1.27 bsc 0.050 bsc j 0.19 0.25 0.008 0.009 k 0.10 0.25 0.004 0.009 m 0 7 0 7 p 5.80 6.20 0.229 0.244 r 0.25 0.50 0.010 0.019 on semiconductor and are registered trademarks of semiconductor components industries, llc (scillc). scillc reserves the right to mak e changes without further notice to any products herein. scillc makes no warranty, representation or guarantee regarding the suitability of its products for an y particular purpose, nor does scillc assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including wi thout limitation special, consequential or incidental damages. ?typical? parameters which may be provided in scillc data sheets and/or specifications can and do vary in different application s and actual performance may vary over time. all operating parameters, including ?typicals? must be validated for each customer application by customer?s technical experts. scillc does not convey any license under its patent rights nor the rights of others. scillc products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the scillc product could create a sit uation where personal injury or death may occur. should buyer purchase or use scillc products for any such unintended or unauthorized application, buyer shall indemnify and hold scillc and its of ficers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, direct ly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that scillc was negligent regarding the design or manufacture of the part. scillc is an equal opportunity/affirmative action employer. this literature is subject to all applicable copyright laws and is not for resale in any manner. publication ordering information n. american technical support : 800 ? 282 ? 9855 toll free usa/canada japan : on semiconductor, japan customer focus center 2 ? 9 ? 1 kamimeguro, meguro ? ku, tokyo, japan 153 ? 0051 phone : 81 ? 3 ? 5773 ? 3850 mc10sx1130/d mosaic iii is a trademark of motorola, inc. literature fulfillment : literature distribution center for on semiconductor p.o. box 61312, phoenix, arizona 85082 ? 1312 usa phone : 480 ? 829 ? 7710 or 800 ? 344 ? 3860 toll free usa/canada fax : 480 ? 829 ? 7709 or 800 ? 344 ? 3867 toll free usa/canada email : orderlit@onsemi.com on semiconductor website : http://onsemi.com order literature : http://www.onsemi.com/litorder for additional information, please contact your local sales representative.
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