unisonic technologies co., ltd lr18115 linear integrated circuit www.unisonic.com.tw 1 of 6 copyright ? 2011 unisonic technologies co., ltd qw-r102-039.d 1.6x linear fan driver with v out fully on control ? description the utc lr18115 is a low output resistance 1.6x positive voltage linear fan driver with ve ry low dropout voltage at up to 500ma. the utc lr18115 consists of an error amplifier, output stage, voltage divider, over temper ature protection, current limiting scheme and fully control logic. v out voltage follows the 1.6 times of v set voltage until it reaches v in voltage. the v set voltage must be larger than 1v to guarantee v out 1.6 times of v set . when given low, v out can be fully turned on by fon pin. good regulation over variation in line, load and temperature is also provided by utc lr18115 . ? features * v out follows 1.6 times of v set * 0.3 ? output resistance @ 0.5a * over temperature protection * current limiting protection * fon pin to turn v out fully on ? ordering information ordering number package packing lead free halogen free LR18115L-S08-R lr18115g-s08-r sop-8 tape reel lr18115l-s08-t lr18115g-s08-t sop-8 tube
lr18115 linear integrated circuit unisonic technologies co., ltd 2 of 6 www.unisonic.com.tw qw-r102-039.d ? pin configuration 1 2 3 4 8 7 6 5 fon v in v out v set gnd gnd gnd gnd ? pin description pin no. name description 1 fon fon input. pulling the regulator fully on when this pin below 0.4v. internally pulled high. 2 v in supply input. 3 v out this pin is output voltage of regulator. its voltage is 1.6 times of v set. 4 v set this pin sets output voltage. its volt age must be larger than 1v to guarantee v out 1.6 times of v set. 5~8 gnd common ground. use all four pi ns on sop-8 device for heat sinking.
lr18115 linear integrated circuit unisonic technologies co., ltd 3 of 6 www.unisonic.com.tw qw-r102-039.d ? block diagram v out fully on logic thermal shutdown current limit v out fon r1=0.6xr2 gnd r1 r2 v in v set
lr18115 linear integrated circuit unisonic technologies co., ltd 4 of 6 www.unisonic.com.tw qw-r102-039.d ? absolute maximum rating (unless otherwise specified ) parameter symbol ratings unit supply input voltage v in -0.3 ~ +7 v enable input voltage v en 0 ~ 7 v power dissipation p d internally limited junction temperature t j +150 c operation temperature t opr -40~+85 c storage temperature t stg -65~+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 and functional device operation is not implied. ? thermal data parameter symbol rating unit junction to ambient ja 156 /w junction to case jc 39 /w ? recommended operating conditions parameter symbol min typ max units supply voltage v cc 4.5 6 v operating temperature t a -40 85 c ? electrical characteristics (v set =2v, v en =5v, v in =5v, i out 0.5a, c in 2.2 f, c out 2.2 f, t a t j 25c, unless otherwise specified )(note) parameter symbol conditions min typ max unit v in supply voltage v cc 4.5 6 v quiescent current i q v out 5v 3 ma v out output voltage/v set voltage set out v v v in =6v,v set =1v~3.3v 1.552 1.6 1.648 v/v line regulation out out v v v in 4.5v to 6v 0.2 0.5 % load regulation out out v v 10ma i out 0.5a 0.2 0.8 % output resistance r out i out 0.5a, v set 3.4v 0.2 0.3 ? current limit i limlt v out =0v 1 a v set minimum v set voltage v set ( min ) 1 v v set pin current i set 80 200 na fon fon voltage fon v high 1.6 v low 0.4 v fon pin bias current fon i fon =0v 1.5 10 a over temperature protection over temperature shutdown ots 150 c over temperature hysteresis oth 25 c note: low duty pulse techniques are used during test to main tain junction temperature as close to ambient as possible.
lr18115 linear integrated circuit unisonic technologies co., ltd 5 of 6 www.unisonic.com.tw qw-r102-039.d ? typical application circuit lr18115 v set fon v in v out gnd v set fon v in v out c in 2.2f c out 2.2f fan v out =1.6v set
lr18115 linear integrated circuit unisonic technologies co., ltd 6 of 6 www.unisonic.com.tw qw-r102-039.d ? typical characteristics 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.
|
