unisonic technologies co., ltd l11810 preliminary cmos ic www.unisonic.com.tw 1 of 6 copyright ? 2010 unisonic technologies co., ltd qw-r502-329.c 1a cmos low dropout voltage ? description as utc ldo, the features of the utc l11810 include low quiescent current and very low dropout voltage. in order to prevent from the bad operating conditions, there are internal thermal shutdown and current fold-back. for stably operation, the utc l11810 should be connected to an output capacitance of 2.2 f or larger. the utc l11810 is 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: 1a (guaranteed) * output voltage accuracy: 1.5% * quiescent current: 30 a * internal over-temperature shutdown * with current limiting * internal short circ uit current fold-back * pre-set output voltages in factory * very low temperature coefficient * halogen free sot-223 1 ? ordering information ordering number package pin assignment packing L11810G-XX-AA3-A-R sot-223 g o i tape reel l11810g-xx-aa3-d-r sot-223 i g o tape reel note: pin assignment: g:gnd o:v out i:v in xx: output voltage, refe r to marking information.
l11810 preliminary cmos ic unisonic technologies co., ltd 2 of 6 www.unisonic.com.tw qw-r502-329.c ? marking information package voltage code marking sot-223 28 :2.8v 33 :3.3v ? pin configuration ? pin description pin no pin name description 1 v in input voltage pin which should be dec oupled with 1f or greater capacitor. 2 gnd ground. 3 v out output voltage pin which should be decoupled with a ceramic capacitor (value: 2.2f or larger and low esr).
l11810 preliminary cmos ic unisonic technologies co., ltd 3 of 6 www.unisonic.com.tw qw-r502-329.c ? block diagram overcurrrent shutdown thermal shutdown gnd r1 r2 v ref =1.215v amp v in v out
l11810 preliminary cmos ic unisonic technologies co., ltd 4 of 6 www.unisonic.com.tw qw-r502-329.c ? absolute maximum rating parameter symbol ratings unit input voltage v in 8 v input ,output voltag e gnd - 0.3 ~ v in + 0.3 v output current i out 1.2 a power dissipation p d 900 mw junction temperature t j 125 c operating temperature t opr - 40 ~ +85 c storage temperature t stg - 65 ~ +150 c note: absolute maximum ratings are those values beyond 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 120 c/w junction to case (note) jc 25 c/w note: measure jc on backside center of tab ? electrical characteristics (ta = 25c, unless ot herwise 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 % 1.8v v out 2.0v -0.15 0.15 % 2.0v < v out < 4.0v -0.1 0.02 0.1 % line regulation out out v v i out =1ma, v in =v out +1~v out +2 v out 4.0v -0.4 0.2 0.4 % load regulation out out v v i out =1ma~1000ma 0.4 1.2 % output current i out v out 1.8v 1000 ma current limit i limit v out 1.8v 1100 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~1000ma 35 a 1.8v v out(nom 2.0v 1700 mv 2.0v < v out(nom 2.8v 1200 mv dropout voltage v d i out =1a v out =v out(nom) -2.0% 2.8v < v out(nom) 1000 mv over temperature shutdown ots 150 c over temperature hysteresis oth 30 c temperature coefficient of output voltage t c v o 30 ppm/c f=100hz 60 db f=1khz 50 db power supply ripple rejection psrr i out =100ma c o =2.2f f=10khz 20 db output voltage noise en i out =10ma, c out =2.2 f, f=10hz~100khz 30 vrms notes: 1. v in(min) =v out +v d 2. to prevent the short circuit curr ent protection feature from being prem aturely activated, the input voltage must be applied before a current source load is applied.
l11810 preliminary cmos ic unisonic technologies co., ltd 5 of 6 www.unisonic.com.tw qw-r502-329.c ? 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 the current exceeds 1100ma, 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 l11810 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.
l11810 preliminary cmos ic unisonic technologies co., ltd 6 of 6 www.unisonic.com.tw qw-r502-329.c 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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