unisonic technologies co., ltd LD1596 preliminary cmos ic www.unisonic.com.tw 1 of 5 copyright ? 2013 unisonic technologies co., ltd qw-r502-a36.a 2a 150khz 40v buck dc/dc converter with led driver and battery charge ? description the utc LD1596 is a 150khz fixed frequency pwm buck (step-down) dc/dc converter, c apable of driving a 2a load with high efficiency. the pwm control circuit is able to adjust the duty ratio linearly from 0~100%. an enable function , an over current protection function is built inside. an internal compensation block is built in to minimize external component count. ? features * wide 4.5v~40v input voltage range * output adjustable from 1.235v~37v * minimum drop out 1.5v * fixed 150khz switching frequency * 2a constant output current capability * internal optimize power transistor * excellent line and load regulation * ttl shutdown capability * on/off pin with hysteresis function sop-8 ? ordering information ordering number package packing lead free halogen free LD1596l-s08-t LD1596g-s08-t sop-8 tube LD1596l-s08-r LD1596g-s08-r sop-8 tape reel
LD1596 preliminary cmos ic unisonic technologies co., ltd 2 of 5 www.unisonic.com.tw qw-r502-a36.a ? pin configuration 1 sw 2 sw 3 gnd 4 fb 8 v in 7 v in 6 en 5 cs utc LD1596 ? pin description pin no. pin name description 1, 2 sw power switch pin (sw). 3 gnd ground pin. 4 fb output control pin 5 cs output current sense pin 6 en enable pin. 7, 8 v in supply voltage input pin. ? block diagram cs fb vin en sw gnd start up 1.23v reference driver thermal shutdown + - + - - + - + - vref vref ovp oscillator 150khz comp ea latch ocp current limit switch + 180mv 60m
LD1596 preliminary cmos ic unisonic technologies co., ltd 3 of 5 www.unisonic.com.tw qw-r502-a36.a ? absolute maximum rating parameter symbol ratings unit input voltage v in -0.3~45 v fb pin voltage v fb -0.3~v in v en pin voltage v en -0.3~v in v sw pin voltage v sw -0.3~v in v power dissipation p d internally limited mw thermal resistance (junction to ambient, no heatsink, free air) r ja 50 c/w operating junction temperature t j -40~125 c storage temperature t stg -65~150 c note: absolute maximum ratings are those values be yond which the device could be permanently damaged. absolute maximum ratings are stress ratings only and functional device oper ation is not implied. ? thermal data parameter symbol ratings unit junction to ambient ja 150 c/w ? electrical characteristics (t a =25c, unless otherwise specified) parameter symbol test conditions min typ max unit system parameters test circuit figure 1 feedback voltage v fb v in =8v~32v, v out =5v, i load =0.2a~2a 1.21 1.235 1.26 v efficiency v in =12v, v out =5v, i out =2a 81 % ? electrical characteristics (dc parameters) v in =12v, gnd=0v, v in & gnd parallel connect a 220uf/50v capacitor; i out =500ma, t a =25c, the others floating unless otherwise specified parameter symbol test conditions min typ max unit input operation voltage v in 4.5 40 v shutdown supply current i stby v en =5v 80 200 ua quiescent supply current i q v en =0v, v fb =v in 2 5 ma oscillator frequency fosc 127 150 172 khz switch current limit i l v fb =0 3 a en pin threshold v en high (regulator off) 1.4 v low (regulator on) 0.8 v output saturation voltage v ce v fb =0v, i sw =2a 1.1 1.4 v constant current sense voltage v cs 0.132 0.155 0.178 v
LD1596 preliminary cmos ic unisonic technologies co., ltd 4 of 5 www.unisonic.com.tw qw-r502-a36.a ? typical application circuit utc LD1596 46 1, 2 7, 8 35 fb vin sw cs gnd en +12~24v d1 1n5821 c out 220uf/35v v out battery l 47uh c1 105 c in 220uf/35v r1 r2 c ff 33nf rcs v out =1.235(1+r2/r1) icharge=0.155v/rcs figure 1. utc typical application circuit (li battery charger) utc LD1596 46 1, 2 7, 8 35 fb vin sw cs gnd en +6~36v sk34 c out 100uf/25v led 1~5w l 33uh c1 105 c in 100uf/50v rcs icharge=0.155v/rcs figure 2. utc typical application circuit (led constant current driver)
LD1596 preliminary cmos ic unisonic technologies co., ltd 5 of 5 www.unisonic.com.tw qw-r502-a36.a utc assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all utc products described or contained herein. utc products are not designed for use in life support appliances, devices or systems where malfunction of these products can be reasonably expected to result in personal injury. reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. the information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice.
|
