unisonic technologies co., ltd lr1125 cmos i c www.unisonic.com.tw 1 of 7 copyright ? 2010 unisonic technologies co., ltd qw-r502-416.a 500ma, low-voltage linear regulator ? description the utc lr1125 is a positive ldo (voltage linear regulator) operates from a 2.25v ~ 5.5v supply and delivers a guaranteed 500ma load current with low 175mv dropout. low dropout voltage and large output current can be provided by built-in low on-resistance transistor. because an internal pmos pass transistor allows low 210a supply current, the lr1125 can be ideal for portable equipment such as pdas, cellular phones, cordless phones, and other equipments including base stations and docking stations. it also includes an acti ve-low, power-ok output that mean a 0.02a shutdown mode, s hort-circuit protection and thermal-shutdown protection when th e output is out of regulation. ? features * low dropout : 175mv dropout at 500ma * high accuracy output voltage: +/- 1.5% * guaranteed output:500ma * thermal-overload protection * internal current limiting * low 210a ground current * 0.02a shutdown current * v out can be adjusted from 0.8v ~ 4.5v ? ordering information ordering number package packing lr1125g-s08-r sop-8 tape reel LR1125G-SM1-R msop-8 tape reel
lr1125 cmos ic unisonic technologies co., ltd 2 of 7 www.unisonic.com.tw qw-r502-416.a ? pin configuration ? pin description pin no pin name description 1, 2 in input. supply voltage: 2.25v ~ 5.5v. bypass with a 1f capacitor to gnd. connect both input pins together. 3 pok open-drain, active-low power-ok output. while the output voltage (v out ) is below the pok threshold, this pin remains low. connect a 100k ? pullup resistor to out. 4 shdn active-low shutdown input. at this pin, a logic low reduces supply current to 0.02a. in shutdown, the pok output is low. for normal operation connect shdn to in. 5 gnd ground. 6 set voltage-setting input. for preset output, connect this pin to gnd. connect an external resistive voltage-divider from out to this pin to set the output voltage from 0.8v to 4.5v. this pin regulation voltage is 800mv. 7, 8 out regulator output (up to 500ma). this pin should be bypassed with a 10f low-esr capacitor to gnd. connect both out pins together.
lr1125 cmos ic unisonic technologies co., ltd 3 of 7 www.unisonic.com.tw qw-r502-416.a ? absolute maximum rating parameter symbol ratings unit in, shdn, pok, set to gnd -0.3~+6 v out to gnd -0.3~(v in +0.3) v output short-circuit duration i d continuous power dissipation (t a =70c) p d 1.95 w junction temperature t j +150 c operating temperature t opr -40~+85 c storage temperature range 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. ? electrical characteristics (v in =v out(setpoint) +500mv or v in =2.25v which is greater, set=gnd, shdn=in, unless otherwise specified. typical values are at t a =25c) t a =0c~85c parameter symbol test conditions min typ max unit input voltage v in 2.25 5.50 v input undervoltage lockout v uvlo rising, 40mv hysteresis 1.85 2 2.15 v i out =100ma -1.5 +1.5 i out =1ma ~ 500ma -2.5 +2.5 output voltage a ccuracy (preset mode) v out t a =0c ~85c, i out =1ma~500ma, v in >v out +0.5v -3 +3 % adjustable output voltage 0.8 4.5 v i out =100ma 788 812 i out =1ma ~ 500ma 780 820 set voltage threshold (adjustable mode) v set t a =0c ~85c, i out =1ma~500ma, v in >v out + 0.5v 774 800 826 mv maximum output current i out 500 ma short-circuit current limit i limit v out =0v 600 1400 2300 ma set dual mode threshold 35 80 125 mv set input bias current i set v set =0.8v -100 +100 na i out =1ma 210 600 ground-pin current i q i out =500ma 575 a i out = 500ma , v out =2.25v 259 400 i out = 500ma , v out =2.8v 201 350 dropout voltage (note 1) v d i out = 500ma , v out =4v 147 275 mv line regulation ? v lnr v in from (v out +100mv)~5.5v, i load =5ma 0 0.125 %/v load regulation ? v ldr i out =1ma ~500ma 15.5 35 ppm/ma output voltage noise 10hz~1mhz, c o =10f(esr<0.1 ? ) 300 v rms shutdown shutdown supply current i off shdn = gnd, v in = 5.5v 0.02 5 a v ih 1.6 shdn input threshold v il 0.6 v shdn input bias current i shdn shdn = gnd or in 10 100 na startup time t start c o =10f,time from shdn high to pok high 40 s
lr1125 cmos ic unisonic technologies co., ltd 4 of 7 www.unisonic.com.tw qw-r502-416.a ? electrical characteristics(cont.) parameter symbol test conditions min typ max unit power-ok pok output low voltage v ol sinking 2ma 5 50 mv operating voltage range for valid pok output sinking 100a 1.0 5.5 v output high leakage current v pok =5.5v 100 na threshold rising edge, referred to v out 90 93 96 % thermal protection thermal-shutdown temperature t shdn 170 c thermal-shutdown hysteresis ? t shdn 20 c t a =-40 c~85 c(note 2) parameter symbol test conditions min typ max unit input voltage v in 2.25 5.50 v input under voltage lockout v uvlo rising, 40mv hysteresis 1.85 2.15 v output voltage accuracy (preset mode) v out i out =1ma~500ma -4 +4 % adjustable output voltage v out(adj) 0.8 4.5 v set voltage threshold (adjustable mode) v set i out =1ma~500ma 766 834 mv maximum output current i out 500 ma short-circuit current limit i lim v out =0v 600 2500 ma set dual mode threshold 35 125 mv set input bias current i set v set =0.8v -100 +100 na ground-pin current i q i out =1ma 400 a shutdown shutdown supply current i off shdn=gnd, v in =5.5v 5 a v ih 2.5v < v in < 5.5v 1.6 shdn input threshold v il 2.5v < v in < 5.5v 0.6 v shdn input bias current i shdn shdn=gnd or in 10 100 na power-ok pok output low voltage v ol sinking 2ma 50 mv operating voltage range for valid pok output sinking 100a 1.0 5.5 v output high leakage current v pok =5.5v 100 na threshold rising edge, referred to v out 89 97 % note 1. dropout voltage is :v in - v out . for 2.25v v out 4v, dropout voltage limits are linearly interpolated from the values listed. for v out < 4v, dropout voltage limit is equal to the value for v out = 4v. 2. specifications to - 40c are guaranteed by design, not production tested.
lr1125 cmos ic unisonic technologies co., ltd 5 of 7 www.unisonic.com.tw qw-r502-416.a ? typical application circuit
lr1125 cmos ic unisonic technologies co., ltd 6 of 7 www.unisonic.com.tw qw-r502-416.a ? typical characteristics (v out = 3.3v, v in = v out + 500mv, shdn = in, c in = 1f, c out = 10f, t a = +25c, unless otherwise noted.)
lr1125 cmos ic unisonic technologies co., ltd 7 of 7 www.unisonic.com.tw qw-r502-416.a ? typical characteristics (cont.) 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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