unisonic technologies co., ltd L4075 preliminary cmos ic www.unisonic.com.tw 1 of 5 copyright ? 2014 unisonic technologies co., ltd qw-r125-030.a 40v led driver with internal switch ? description the utc L4075 is a continuous conduction mode inductive step-down converter, designed for driving single or multiple series connected leds efficiently from a voltage source higher than the total leds chain voltage. the chip operates from an input supply between 6v and 40v and provides an externally adjustable output current of up to 750ma (sot89-5). depending upon supply voltage and external components, this c an provide up to 30w of output power. the utc L4075 includes an integrated output switch and a high-side output current sensing circuit, which uses an external resistor to set the nominal average output current. output current can be adjusted linearly by applying an external control signal to the adj pin. the adj pin will accept either a dc voltage dimming or a wide range of pulsed dimming. this will provide either a continuous or a gated output current. applying a voltage of 0.2v or lowe r to the adj pin can turn the output off and switch the chip in to a low current standby state. ? features * 6v~40v input voltage range * simple low parts count * internal 40v power switch * high efficiency up to 95% * typical 5% output current accuracy * single pin on/off and brightness control using dc voltage or pwm * up to 1mhz switching frequency * protection features: open-circuit led protection thermal shutdown protection ? ordering information ordering number package packing lead free halogen free L4075l-af5-r L4075g-af5-r sot-25 tape reel
L4075 preliminary cmos ic unisonic technologies co., ltd 2 of 5 www.unisonic.com.tw qw-r125-030.a ? marking ? pin configuration ? pin description pin no. pin name description 1 lx drain of power switch 2 gnd ground (0v) 3 adj multi-function on/off and brightness control pin 4 i sense current sense input 5 v in input voltage ? block diagram +
L4075 preliminary cmos ic unisonic technologies co., ltd 3 of 5 www.unisonic.com.tw qw-r125-030.a ? absolute maximum rating parameter symbol ratings unit input voltage v in -0.3~+50 v i sense voltage v in >5v v isense v in +0.3~v in -5 v v in <5v v in +0.3~ -0.3 v lx output voltage v l x -0.3~+50 v adjust pin input voltage v adj -0.3~+6 v switch output current i l x 400 ma power dissipation p d 600 mw operating junction temperature t j 150 c operating temperature range t opr -40~85 c storage temperature range t stg -55~150 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 characteristics parameter symbol max unit junction to ambient ja 270 c/w
L4075 preliminary cmos ic unisonic technologies co., ltd 4 of 5 www.unisonic.com.tw qw-r125-030.a ? electrical characteristics (v in =12v, t amb =25c unless otherwise stated) (note 1) parameter symbol test conditions min typ max unit input voltage v in 6 40 v quiescent supply current with output off i inqoff adj pin grounded 40 60 80 a quiescent supply current with output switching i inqon adj pin floating 450 600 a mean current sense threshold voltage v sense 113 mv sense threshold hysteresis v sensehys 15 % i sense pin input current i sense v sense =0.1v 8 10 a internal reference voltage v ref measured on adj pin with pin floating 1.2 v external control voltage range on adj pin for dc brightness control v adj 0.3 1.2 v dc voltage on adj pin to switch chip from active (on) state to quiescent (off) state v adjoff v adj falling 0.15 0.2 0.25 v dc voltage on adj pin to switch chip from quiescent (off) state to active (on) state v adjon v adj rising 0.2 0.25 0.3 v resistance between adj pin and v ref r adj 500 k ? continuous lx switch current i lxmean 0.35 a lx switch leakage current i lx ( leak ) 1 a lx switch ?on? resistance r lx 0.9 1.5 ? minimum switch ?on? time t onmin lx switch ?on? 200 ns minimum switch ?off? time t offmin lx switch ?off? 200 ns brightness control range at low frequency pwm signal d pwm(lf) pwm frequency=100hz, pwm amplitude=5v, v in =15v, driving 1led, l=27 h 1200:1 brightness control range at low frequency pwm signal d pwm(hf) pwm frequency=10khz, pwm amplitude=5v, v in =15v, driving 1led, l=27 h 13:1 operating frequency f lx adj pin floating l=100 h (0.82 ? ) i out =350ma @ v led =3.4v driving 1 led 154 khz recommended maximum operating frequency f lxmax 1 mhz recommended duty cycle range of output switch at f lxma x d lx 0.3 0.7 0.9 internal comparator propagation delay t pd 50 ns thermal shutdown temperature t sd 140 c thermal shutdown hysteresis t sd-hys 20 c note: production testing of the chip is performed at 25c. functional operation of the chip and parameters specified are guaranteed by design, characterization and process control in other temperature.
L4075 preliminary cmos ic unisonic technologies co., ltd 5 of 5 www.unisonic.com.tw qw-r125-030.a ? typical application circuit v in i sense lx gnd utc L4075 v in (dc)= 6v~40v r s =0.15 c1 1f d1 l1 47h up to 10 leds adj 5 4 1 2 3 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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