unisonic technologies co., ltd l1188 preliminary cmos ic www.unisonic.com.tw 1 of 4 copyright ? 2012 unisonic technologies co., ltd qw-r502-324.d 800ma cmos ldo ? description as utc ldo, the features of the utc l1188 include low quiescent current and very low dropout voltage. in order prevent form the bad operating conditions, there are internal thermal shutdown and current fold-back. for stably operation, the utc l1188 should be connected to an output capacitance of 2.2 f or larger. the utc l1188 can be an ideal for battery applications, such as portable electronics, wireless devices, cordless phones, pc peripherals and battery powered widgets. ? features * extra low dropout voltage * output current: 800ma (guaranteed) * output voltage accuracy: 1.5% * quiescent current: 30 a * internal over-temperature shutdown * with current limiting * internal short circuit current fold-back * pre-set output voltages in factory * very low temperature coefficient sot-223 1 ? ordering information ordering number package pin assignment packing lead free halogen free 1 2 3 L1188L-XX-AA3-A-R l1188g-xx-aa3-a-r sot-223 g o i tape reel note: pin assignment: g:gnd o:v out i:v in xx: output voltage, refe r to marking information.
l1188 preliminary cmos ic unisonic technologies co., ltd 2 of 4 www.unisonic.com.tw qw-r502-324.d ? marking information package voltage code marking sot-223 28 :2.8v 33:3.3v ? pin configuration ? pin description pin no. pin name description 1 gnd ground. 2 v out output voltage pin which should be de coupled with a ceramic capacitor (value: 2.2f or larger and low esr). 3 v in input voltage pin which should be dec oupled with 1f or greater capacitor. ? block diagram overcurrrent shutdown thermal shutdown gnd r1 r2 v ref =1.215v amp v in v out
l1188 preliminary cmos ic unisonic technologies co., ltd 3 of 4 www.unisonic.com.tw qw-r502-324.d ? absolute maximum rating parameter symbol ratings unit input, output voltage gnd - 0.3 ~ v in + 0.3 v input voltage v in 8 v output current i out 1 a power dissipation p d 800 mw junction temperature t j 125 c ambient operating temperature t opr - 40 ~ +85 c storage temperature t stg - 65 ~ +150 c notes: absolute maximum ratings are those values beyond which the device could be permanently damaged. absolute maximum ratings are stress ratings only and functional device operation is not implied. ? thermal data parameter symbol ratings unit junction to ambient ja 135 c/w junction to case (note) jc 31 c/w note: measure jc on backside center of tab. ? electrical characteristics (t a = 25c, unless otherwise specified.) parameter symbol test conditions min typ max unit input voltage v in note1 7 v output voltage accuracy v out i out = 1ma -1.5 1.5 % line regulation out out v v i out =1ma v in =v out +1~v out +2 1.8v v out 2.0v -0.15 0.15 % 2.0v < v out < 4.0v -0.1 0.02 0.1 % v out 4.0v -0.4 0.2 0.4 % load regulation out out v v i out =1ma~800ma 0.2 1 % output current i out v out 1.8v 800 ma current limit i limit v out 1.8v 900 ma short circuit current i sc v out < 0.8v 400 800 ma quiescent current i q i out =0ma 30 50 a ground pin current i gnd i out =1ma ~ 800ma 35 a dropout voltage v d i out =800ma v out =v out(nom) -2.0% 1.8v v out ( nom ) 2.0v 1400 mv 2.0v l1188 preliminary cmos ic unisonic technologies co., ltd 4 of 4 www.unisonic.com.tw qw-r502-324.d ? typical application circuit ? application information 1. detailed description internal circuits include: a pmos pass transistor, voltage reference, error amplifier, over-current protection, and thermal shutdown. the data through the error amplifier, over-current shutdown, and therma l protection circuits, then to the p-channel pass transistor. as soon as the junction temperature exceeds 150c or th e current exceeds 900ma, over-current and thermal shutdown circuits start working. when the junction temper ature drops below 120c, nor mal operation is restored. when the load exceeds the rated output current, for preventing the over stress, the chip switches from voltage mode to current mode. 2. external information when considering the external capac itors, the l1188 is stable with an output capacitor to ground of 2.2 f or greater. as we know, the ceramic capacitors have the lo west esr but can offer the best ac performance; the aluminum electrolytic capacitors exhibit the highest esr but offer the poorest ac response. and also large value ceramic capacitors are expensive. consider all th e situation, the best way is to parallel a 0.1 f ceramic capacitor with a 10 f aluminum electrolytic (low esr, high capacitance, and low overall cost). for better beneficial effecting, the input capacitor should be at least 0.1 f. 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.
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