1235 bordeaux drive, sunnyvale, ca 94089 tel: 408-222-8888 www.supertex.com cl325 general description the cl325 is designed to drive 3 strings of leds at a constant current of 25ma. other drivers with currents in the range of 20 - 30ma are available. the drive current is ?xed, with a 6% tolerance over a v out range of 4 - 15v. separate enable pins for each channel allow for pwm dimming, 3-step linear dimming, or individual disconnection of faulty led strings. over-temperature protection circuitry shuts down all 3 channels when the nominal die temperature reaches 135c. normal operation resumes when the die temperature drops by 30c. the cl325 is available in the 8-lead soic (w/heat slug) package and requires a single ceramic bypass capacitor which may be shared among several drivers. block diagram and typical application circuit 3-channel 25ma linear led driver features 6% current accuracy @ 4.0 -15v 90v standoff voltage separate enable pins for each channel allow for pwm dimming over-temperature protection 8-lead soic (w/heat slug) package applications lcd backlightingindicator lamps ?? ? ? ? ? ? en1 en2 en3 out1 out2 out3 gnd v dd 6.5 - 90v cl325 reg vin host controller 12 3 8 7 6 5 4 c in 100nf downloaded from: http:///
2 cl325 1235 bordeaux drive, sunnyvale, ca 94089 tel: 408-222-8888 www.supertex.com en1 gnd en2 en3 vin out3 out1 out2 underside plate is ground -g indicates package is rohs compliant (green) absolute maximum ratings parameter value supply voltage, v in -0.5v to +100v output voltage, v out -0.5v to +100v enable voltage, v en -0.5v to +6.5v operating temperature (1) -40c storage temperature -65c to +150c thermal characteristics absolute maximum ratings are those values beyond which damage to the device may occur. functional operation under these conditions is not implied. continuous operation of the device at the absolute rating level may affect device reliability. all voltages are referenced to device ground. note: maximum junction temperature internally limited. 1. pin con?guration 8-lead soic (w/heat slug) (sg) product marking yy = year sealed ww = week sealed l = lot number = green packaging yyww cl325 l l l l 8-lead soic (w/heat slug) (sg) sym parameter min typ max units conditions v in supply voltage 6.5 - 90 v --- v out output voltage 4.0 - 15 v en = 0 90 v en = 1 f en enable toggling frequency 0 - 100 khz --- t j junction temperature -40 - 119 o c --- c in v in capacitor - 100 - nf --- recommended operating conditions (all voltages with respect to gnd pin) sym parameter min typ max units conditions ja thermal resistance,junction to ambient - 48 - o c/w mounted on jedec test pcb (2s 2p) t lim over-temperature limit 120 135 150 o c --- t hys over-temperature hysteresis - 30 - o c --- ordering information device 8-lead soic (w/heat slug) 4.90x3.90mm body 1.70mm height (max) 1.27mm pitch cl325 CL325SG-G downloaded from: http:///
3 cl325 1235 bordeaux drive, sunnyvale, ca 94089 tel: 408-222-8888 www.supertex.com electrical characteristics (over recommended operating conditions. t a @ 25 o c unless otherwise speci?ed.) sym parameter min typ max units conditions i in v in supply current - 220 250 a en 1-3 = 1 - 2.2 2.3 ma en 1-3 = 0 i out(off) output current, off - 4.0 10 a en x = 1 i out(on) output current, on - - 26.5 ma en x = 0, v out = 0 - 4.0v 23.5 25.0 26.5 en x = 0, v out = 4.0 - 15v 22.5 25.0 27.5 en x = 0, v out = 15 - 90v v en(on) enable voltage, on - - 0.8 v --- v en(off) enable voltage, off 2.4 - - v --- c en enable input capacitance - 5.0 10 pf --- i enl enable low input current - - 1.0 a v en = 0v i enh enable high input current - - 1.0 a v en = 5.0v t on enable on delay - 2.0 2.4 s --- t rise output current rise time - 1.0 1.2 s --- t off enable off delay - 440 800 ns --- t fall output current fall time - 170 250 ns --- timing temperature effects t rise t fall 90% i out(on) en i out v en(on) v en(off) t on t off 10% i out(on) 1.00 1.05 0.95 -50 0 50 100 150 junction temperature (c) 0.90 0.85 0.80 c u r r e n t ( n o r m a l i z e d t o 2 5 c ) 120 25 -40 downloaded from: http:///
4 cl325 1235 bordeaux drive, sunnyvale, ca 94089 tel: 408-222-8888 www.supertex.com load regulation 0 5 10 15 20 40 60 80 100 scale change i o u t ( n o r m a l i z e d to n o m in a l ) 0 0.20 0.40 0.60 0.80 1.00 1.20 v out (v) recommended pcb layout underside plate soldered to copper area exposed copper areamay be plated 1cm 2 exposed copper 1cm 2 exposed copper higher led current en1 en2 en3 out1 out2 out3 gnd v dd v ll cl325 reg vin host controller 12 3 8 7 6 5 4 c in 100nf by paralleling outputs, higher led currents can be achieved. in addition, linear dimming in 3 discre te steps may be obtained by enabling 1, 2, or 3 outputs. downloaded from: http:///
5 cl325 1235 bordeaux drive, sunnyvale, ca 94089 tel: 408-222-8888 www.supertex.com lowering cl325 power dissipation: separate v in supply en1 en2 en3 out1 out2 out3 gnd v dd cl325 reg vin host controller 12 3 8 7 6 5 4 c in 100nf v in v ll cl325 power dissipation may be lowered by supplying the cl325 from a voltage source (v in ) that is lower in voltage than the led supply (v ll ). lowering cl325 power dissipation: dropping resistor en1 en2 en3 out1 out2 out3 gnd v dd cl325 reg vin host controller 12 3 8 7 6 5 4 v ll r drop r drop < v ll(min) - 6.5v 2.3ma where: r drop = dropping resistance v ll(min) = minimum supply voltage c in 100nf downloaded from: http:///
6 cl325 1235 bordeaux drive, sunnyvale, ca 94089 tel: 408-222-8888 www.supertex.com lowering cl325 power dissipation: zener diode en1 en2 en3 out1 out2 out3 gnd v dd cl325 reg vin host controller 12 3 8 7 6 5 4 v ll z drop v z < (v ll(min) - 6.5v) where: v z = zener voltage v ll(min) = minimum supply voltage c in 100nf pin description pin # name description 1 en1 output enable, active low. 2 en2 3 en3 4 gnd circuit common. 5 out3 constant current output (sinking). connect the cathodes of the leds to these pins. 6 out2 7 out1 8 vin supply voltage. 6.5v to 90v. bypass locally with a 100nf capacitor to ground. underside plate gnd the exposed underside plate is internally connected to the gnd pin. the plate may either be left ?oating or connected to ground. solder the plate to an exposed copper area on the pcb for heatsinking purposes (see recommended layout). downloaded from: http:///
supertex inc. does not recommend the use of its products in life support applications, and will not knowingly sell them for use in such applications unless it receive s an adequate product liability indemnification insuran ce agreement. supertex inc. does not assume responsibility for use of devices described, and limits its liability to the replacement of the devices determined defective due to workmanship. no responsibility is assumed for p ossible omissions and inaccuracies. circuitry and s pecifications are subject to change without notice. for the lates t product specifications refer to the supertex inc. website: http//www.supertex.com. ?2008 all rights reserved. unauthorized use or reproduct ion is prohibited. 1235 bordeaux drive, sunnyvale, ca 94089 tel: 408-222-8888 www.supertex.com 7 cl325 (the package drawing(s) in this data sheet may not re?ect the most current speci?cations. for the la test package outline information go to http://www.supertex.com/packaging.html .) doc.# dsfp-cl325 a091508 8-lead soic (narrow body w/heat slug) package outline (sg) 4.90x3.90mm body, 1.70mm height (max), 1.27mm pitch symbol a a1 a2 b d d1 e e1 e2 e h l l1 l2 1 dimension (mm) min 1.25* 0.00 1.25 0.31 4.80* 3.30 ? 5.80* 3.80* 2.29 ? 1.27 bsc 0.25 0.40 1.04 ref 0.25 bsc 0 o 5 o nom - - - - 4.90 - 6.00 3.90 - - - - - max 1.70 0.15 1.55* 0.51 5.00* 3.81 ? 6.20* 4.00* 2.79 ? 0.50 1.27 8 o 15 o jedec registration ms-012, variation ba, issue e, sept. 2005. * this dimension is not speci?ed in the original jedec drawing. the value listed is for reference on ly. ? this dimension is a non-jedec dimension. drawings not to scale. supertex doc. #: dspd-8sosg, version c090408. d seating plane gauge plane l l1 l2 top view side view view a - a view b view b 1 e1 e a a2 a1 a a seating plane e b h h 8 1 d1 e2 bottom view exposed thermal pad zone note 1 note 1 (index area d/2 x e1/2) 8 1 notes: a pin 1 identi?er must be located in the index area indicated. the pin 1 identi?er can be: a molded mark/identi?er; an embedded metal marker; or a printed indicator. 1. downloaded from: http:///
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