CL320 general description the CL320 is designed to drive 3 strings of leds at a constant current of 20ma. 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 CL320 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 20ma 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 backlighting indicator lamps ? ? ? ? ? ? ? en1 en2 en3 out1 out2 out3 gnd v dd 6.5 - 90v CL320 reg vin host controller 1 2 3 8765 4 c in 100nf
2 CL320 en1 gnd en2 en3 vin out3 out1 out2 underside plate is ground ordering information device 8-lead soic (w/heat slug) CL320 CL320sg-g -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: (1) maximum junction temperature internally limited. pin con? guration 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 --- 8-lead soic (w/heat slug) (sg) product marking yy = year sealed ww = week sealed l = lot number = green packaging yyww CL320 llll 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)
3 CL320 electrical characteristics (over recommended operating conditions. t j @ 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 - - 21.2 ma en x = 0, v out = 0 - 4.0v 18.8 20.0 21.2 en x = 0, v out = 4.0 - 15v 18.0 20.0 22.0 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
4 CL320 pin description pin # name description 1,2,3 en1, en2, en3 output enable, active low. 4 gnd circuit common. 5,6,7 out1, out2, out3 constant current output (sinking). connect the cathodes of the leds to these pins. 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). 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 area may be plated 1cm 2 exposed copper 1cm 2 exposed copper
5 CL320 higher led current en1 en2 en3 out1 out2 out3 gnd v dd v ll CL320 reg vin host controller 1 2 3 8765 4 c in 100nf by paralleling outputs, higher led currents can be achieved. in addition, linear dimming in 3 discrete steps may be obtained by enabling 1, 2, or 3 outputs. lowering CL320 power dissipation: separate v in supply en1 en2 en3 out1 out2 out3 gnd v dd CL320 reg vin host controller 1 2 3 8765 4 c in 100nf v in v ll CL320 power dissipation may be lowered by supplying the CL320 from a voltage source (v in ) that is lower in voltage than the led supply (v ll ).
6 CL320 lowering CL320 power dissipation: dropping resistor lowering CL320 power dissipation: zener diode en1 en2 en3 out1 out2 out3 gnd v dd CL320 reg vin host controller 1 2 3 8765 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 en1 en2 en3 out1 out2 out3 gnd v dd CL320 reg vin host controller 1 2 3 8765 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
7 CL320 (the package drawing(s) in this data sheet may not re? ect the most current speci? cations. for the latest package outline information go to http://www.supertex.com/packaging.html .) 8-lead soic (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 1.70 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. dimensions marked with (*) are non-jedec dimensions. drawings not to scale. 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 note 1: this chamfer feature is optional. if it is not present, then a pin 1 identi? er must be located in the index area indicated.the pin 1 identi? er may be either a mold, or an embedded metal or marked feature. doc.# dsfp-CL320 nr111207
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