unisonic technologies co., ltd lr478 linear integrated circuit www.unisonic.com.tw 1 of 8 copyright ? 2005 unisonic technologies co., ltd qw-r119-003.b regulator+reset ic ? description the utc lr478 developed for use in cd-rom drives, combines a 3v regulator adapted to low power consumption with a much-sought reset function (regulator input monitoring),with internal delay circuit, set to detect 4.2v. ? features *large output current: 300ma (max.) *high ripple rejection rate: 80db(typ.) *internal thermal shutdown circuit *internal current limiting circuit *easy set delay time from voltage detection to reset release sop-8 *pb-free plating product number: lr478l ? ordering information order number normal lead free plating package packing lr478-xx-s08-r LR478L-XX-S08-R sop-8 tape reel lr478-xx-s08-t lr478l-xx-s08-t sop-8 tube note: xx: output voltage, refer to rank list as below. ? output detection voltage rank list part number regulator output volt age (v) detection voltage (v) lr478-3.4v 3. 400.05 4.200.09 lr478-3.3v 3. 300.05 4.200.09 lr478-2.5v 2. 500.05 4.200.09
lr478 linear integrated circuit unisonic technologies co., ltd 2 of 8 www.unisonic.com.tw qw-r119-003.b ? pin configuration 8 7 6 5 1 2 3 4 n.c reset cont v in v out n.c gnd cd ? pin description pin no. pin name functions equivalent circuit diagram 1 n.c 2 reset input voltage detection output input voltage detection output pin reset pin logic reset v in v s h reset 3 cont output voltage on/off-control pin v cont output l off h on connect cont-terminal with v in when it is not used. cont 300k 400k 4 v in voltage supply input pin 5 v out regulator output pin 6 n.c 7 gnd gnd pin 8 cd delay time capacitor pin reset pin output delay time can be set by the capacitance connected to the cd pin. t plh =100000.c t plh : transmission delay time[s] c: capacitor value [f] + - v out cd
lr478 linear integrated circuit unisonic technologies co., ltd 3 of 8 www.unisonic.com.tw qw-r119-003.b ? black diagram reset cont v in v out gnd cd thermal protect 3 4 5 2 7 8 + - + - + - + -
lr478 linear integrated circuit unisonic technologies co., ltd 4 of 8 www.unisonic.com.tw qw-r119-003.b ? absolute maximum ratings parameter symbol ratings unit supply voltage v in -0.3 ~ +10 v output current i out 400 ma power dissipation(note3) p d 700 mw junction temperature t j +125 c operating temperature t opr -40 ~ +85 c storage temperature t stg -40~+150 c note 1. absolute maximum ratings are those values beyond which the device could be permanently damaged. absolute maximum ratings are stress ratings only an d functional device operat ion is not implied. 2. the device is guaranteed to meet performance specification within 0 ~ +70 operating temperature range and assured by design from ?20 ~ +85 . ? recommended operation conditions parameter symbol ratings unit operating voltage v opr 0 ~ 10 v output current i out 0 ~ 300 ma ? electrical characteristics (v cont =1.6v, ta=25 c, unless otherwise specified ) parameter symbol test conditions min typ max unit no-load input current 1 i q 1 v in =5v, i out =0ma 3 8 ma no-load input current 2 i q 2 v in =4v, i out =0ma 4 ma input current (off) i q 3 v in =5v, v cont =0.4v 250 a regulator output voltage v out v in =5v, i out =30ma 3.33 3.40 3.47 v input-output different voltage v i/o(diff) v in =3.2v, i out =150ma 0.15 0.3 v line regulation v out v in =4.4~5.5v, i out =30ma 10 20 mv load regulation v out v in =5v, i out =0~300ma 20 120 mv v out temperature coefficient v out / tv in =5v, i out =30ma, t j = -20~85 c 100 ppm/ c ripple rejection rr v in =5v, i out =30ma, f=120hz v ripple =1v p-p 50 80 db output noise voltage v in v in =5v, i out =30ma, f=20~80khz 40 120 vrms cont terminal current i cont v cont =1.6v 5 10 a high threshold voltage v thr(h) 1.6 v in +0.3 v low threshold voltage v thr(l) -0.3 0.4 v reset detection voltage vs v in = v thr(h) v thr(l) 4.11 4.20 4.29 v vs temperature coefficient v s / tt j = -20~85 c 100 ppm/ c hysteresis voltage v hys v in = v thr(h) v thr(l) v thr(h) 100 200 mv low-level output voltage v ol v in =3.9v, r l =4.7k 100 200 mv output leakage current i leak v in =5v 0.1 a output current 1 i out 1 v in =3.9v, r l =0 5 ma output current 2 i out 2 v in =3.9v, r l =0, ta= -20~85 c 3 ma ?h? transmission delay time t plh cd =0.0 f 30 90 s reset delay time t plh 1 v in =4v 5v, cd =0.1 f 5 10 20 ms ?l? transmission delay time t plh 30 90 s threshold operating voltage v thr(opr) v ol =0.4v 0.65 0.85 v
lr478 linear integrated circuit unisonic technologies co., ltd 5 of 8 www.unisonic.com.tw qw-r119-003.b ? test circuit a cont + v out cd 4 2 utc lr478 5 8 a v 3 7 6 reset gnd v in 1 f 47 f 0.1 f 4.7k ? typical application circuit cont + v out cd 4 2 utc lr478 5 8 3 7 6 reset gnd v in 1 f 47 f 0.1 f 4.7k c out note: external output-capacitor(c out ) for stability is necessary due to without internally compensated.
lr478 linear integrated circuit unisonic technologies co., ltd 6 of 8 www.unisonic.com.tw qw-r119-003.b ? timing chart cont reset v in v out 5v v s ov vs h l 5v ov 5v ov t plh 1
lr478 linear integrated circuit unisonic technologies co., ltd 7 of 8 www.unisonic.com.tw qw-r119-003.b ? typical characteristics 5 234 1 0 3 5 2 1 output voltage (v) input voltage (v) detection voltage 4 0 v out reset i out =0ma 25 50 0 -25 3.42 3.5 3.38 3.34 output voltage (v) temperature ( ) output volttage vs temperature 3.46 3.3 3.48 3.44 3.4 3.36 3.32 100 75 125 9 67 8 5 4 20 -10 line regulation (mv) input voltage (v) line regulation 10 -20 10 15 5 0 -5 -15 load regulation (mv) output current (ma) 300 250 100 150 200 50 0 30 -10 load regulation 10 20 0 -20 -30 1000 10000 100 10 60 100 40 20 ripple rejection (db) frequency (hz) ripple rejection 80 0 90 70 50 30 10 100000 output voltage (v) temperature ( ) detecting volttage vs temperature 25 50 0 -25 4.22 4.3 4.18 4.14 4.26 4.1 4.28 4.24 4.2 4.16 4.12 100 75 125
lr478 linear integrated circuit unisonic technologies co., ltd 8 of 8 www.unisonic.com.tw qw-r119-003.b ? typical characteristics(cont.) temperature ( ) 125 50 75 100 25 0 600 1000 400 200 allowable loss (mv) allowable loss 800 0 on board 25*40*1mm utc assumes no responsib ility 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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