unisonic technologies co., ltd u8021 preliminary cmos ic www.unisonic.com.tw 1 of 6 copyright ? 2013 unisonic technologies co., ltd qw-r502-a13.a voltage mode pwm controller with linear power regulator ? description the utc u8021 provides the control and protection features necessary for a synchronous buck converter and a linear regulator in high performance graphic card applications. the utc u8021 is designed to directly drive the high and low mosfets of the buck converter. it allows the converter to operate with 4v~25v power rail and as low as 0.5v output. the utc u8021 is capable to drive a n-type mosfet in a linear regulator with as low as 0.5v output. the utc u8021 features soft-start, uvlo, and ocp. the utc u8021 monitors the output current by using the rdson of the low mosfet in the buck converter that eliminates the need for a current sensing resistor. ? features * 4v~25v power rails * internal ldo * 1.5a gate drive current * adaptive non-overlapping gate drives provide shoot-through protection for mosfets * programmable output voltages * internal soft start * under voltage lockout * short circuit protection ? ordering information ordering number package packing lead free halogen free u8021l-s14-t u8021g-s14-t sop-14 tube u8021l-s14-r U8021G-S14-R sop-14 tape reel
u8021 preliminary cmos ic unisonic technologies co., ltd 2 of 6 www.unisonic.com.tw qw-r502-a13.a ? pin configuration ? pin description pin no. pin name description 1 bst boost input for top gate drive bias. 2 ocs current limit setting. 3 comp compensation pin. 4 fb feedback voltage 5 ldog external ldo gate drive. 6 ldfb external ldo feedback voltage. 7 gnd ground. 8 v cc power supply. 9 nc no bonding. 10 drv internal ldo output. 11 dl gate drive for low mosfet. 12 gnd ground. 13 pn phase pin. 14 dh gate drive for high mosfet.
u8021 preliminary cmos ic unisonic technologies co., ltd 3 of 6 www.unisonic.com.tw qw-r502-a13.a ? block diagram osc ldo uvlo soft sart r s latch bandgop ea pwm ocp ocs v cc bias v cc ldo-reg driver comp fb ldog ldfb pn gnd dl drv dh bst
u8021 preliminary cmos ic unisonic technologies co., ltd 4 of 6 www.unisonic.com.tw qw-r502-a13.a ? absolute maximum rating exceeding the specifications below may result in permanent damage to the devic e, or device malfunction. operation outside of the parameters specifi ed in the electrical characteristics section is not implied. parameter symbol ratings unit input supply voltage v cc 18 v bst to gnd v bst 40 v bst to pn v bst _ pn 10 v pn to gnd v pn -1~30 v pn to gnd negative pulse (t p ulse <20ns) v pn _ pulse -5 v dl to gnd v dl -1~+10 v dl to gnd negative pulse (t p ulse <20ns) v dl _ pulse -3 v dh to pn v dh _ pn -1~+10 v dh to pn negative pulse (t p ulse <20ns) v dh _ pulse -3 v drv to gnd v drv 10 v operating ambient temperature range t a -25~85 c operating junction temperature t j -25~125 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 resistances parameter symbol ratings unit junction to ambient ja 100 c/w junction to case jc 32 c/w
u8021 preliminary cmos ic unisonic technologies co., ltd 5 of 6 www.unisonic.com.tw qw-r502-a13.a ? electrical characteristics (unless specified: v cc = 5v~16v, v fb =v out , v bst -v pn =5v~8.2v, t a =-25c~85c) parameter symbol test conditions min typ max unit general v cc supply voltage v cc 4 16 v v cc quiescent current i qvcc v cc =12v, v bst -v pn =8.2v 5 7 ma v cc under voltage lockout uv vcc v hyst =100mv 4 v bst to pn supply voltage v bst _ pn 4 10 v bst quiescent current i qbst v cc =12v, v bst -v pn =8.2v 3 ma internal ldo ldo output v drv 8.6v u8021 preliminary cmos ic unisonic technologies co., ltd 6 of 6 www.unisonic.com.tw qw-r502-a13.a ? typical application circuit 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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