unisonic technologies co., ltd usr1101 preliminary linear integrated circuit www.unisonic.com.tw 1 of 5 copyright ? 2015 unisonic technologies co., ltd qw-r103-062.b 5v/12v synchronous buck pwm dc-dc controller ? description the utc usr1101 is a high efficiency synchronous buck pwm controller, with operating at fixed 300khz frequency, internal soft-start, frequency compensation networks and integrates all of the control, output adjustment, monitoring and protection functions into a single package. adjustable over-current protec tion (ocp) monitors the voltage drop across the r ds(on) of the lower mosfet for synchronous buck pwm dc-dc controller. ? features * operating with 5v or 12v supply voltage * drives all low cost n-channel mosfets * pwm control mode * 300khz fixed frequency * internal soft-start * over-current fault monitor on mosfet, no current sense resistor required * rohs compliant and 100% lead (pb)-free sop-8 ? ordering information ordering number package packing usr1101g-s08-r sop-8 tape reel usr1101g-s08-r (1)packing type (2)package type (3)green package (1) r: tape reel (2) s08: sop-8 (3) g: halogen free and lead free ? marking
usr1101 preliminary linear integrated circuit unisonic technologies co., ltd 2 of 5 www.unisonic.com.tw qw-r103-062.b ? pin configuration v cc 1 2 3 4 8 7 6 5 boot ugate gnd lgate fb ops nc usr1101 ? pin description pin no. pin name description 1 boot high-side gate drive boost 2 ugate upper gate driver output 3 gnd ground 4 lgate lower gate drive output 5 v cc supply voltage 6 fb feedback voltage 7 ops over-current setting and shutdown 8 nc no bonding
usr1101 preliminary linear integrated circuit unisonic technologies co., ltd 3 of 5 www.unisonic.com.tw qw-r103-062.b ? block diagram
usr1101 preliminary linear integrated circuit unisonic technologies co., ltd 4 of 5 www.unisonic.com.tw qw-r103-062.b ? absolute maximum rating parameter symbol ratings unit supply voltage v cc 16 v power dissipation (t a =25c) (note 1) p d 0.625 w storage temperature t stg -65~150 c junction temperature t j 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 data parameter symbol ratings unit junction to ambient ja 160 /w ? recommended operating conditions (note 2) parameter symbol ratings unit supply voltage v cc 55%,1210% v ambient temperature t a 0~70 c junction temperature t j 0~125 c notes: 1. ja is measured in the natural convection at t a =25c on a low effective thermal conductivity test board of jedec 51-3 thermal m easurement standard. 2. the device is not guaranteed to f unction outside its operating conditions. ? electrical characteristics (v cc =5v/12v, t a =25c, unless otherwise specified) parameter symbol test conditions min typ max unit v cc supply current nominal supply current i cc ugate and lgate open 6 15 ma power-on reset por threshold v ccrth v cc rising 4.1 4.5 v hysteresis v cchys 0.35 0.5 v switcher reference reference voltage v ref v cc =12v 0.784 0.8 0.816 v oscillator free running frequency f osc v cc =12v 250 300 350 khz ramp amplitude ? v osc v cc =12v 1.5 v p-p pwm controller gate drivers (v cc =12v) dead time t dt 100 ns protection fb under-voltage trip ? fbuvt fb falling 70 75 80 % oc current source i oc 40 45 a soft-start interval t ss 2.5 ms
usr1101 preliminary linear integrated circuit unisonic technologies co., ltd 5 of 5 www.unisonic.com.tw qw-r103-062.b ? application information ocp sense the low-side mosfet?s r ds(on) to set over-current trip point. connecting a resistor (r ocset ) from this pin to the source of the upper mosfet and the drain of the lower mosfet sets the over-current trip point. r ocset , an internal 40 a current source, and the lower mosfet on resistance, r ds(on) , set the converter over-current trip point (i ocset ) according to the following equation: mosfet lower the of r 0.4v r a 40 i ds(on) ocset ocset ? ? ? ? shutdown pulling low the ops pin by a small single transistor can shutdown the utc usr1101 pwm controller as shown in typical application circuit. ? typical application circuit boot c out 1000f3 m1 c2 0.1f c3 1f c4 470f v in +5v~+12v d1 1n4148 c1 1f r1 10 l1 3h v out r2 32 r3 68 r4 200-1k c5 0.1-0.33f 1 5 2 8 67 3 4 v cc fb gnd lgate ops nc ugate disable r ocset m2 utc usr1101 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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