unisonic technologies co., ltd UC3658 preliminary cmos ic www.unisonic.com.tw 1 of 4 copyright ? 2014 unisonic technologies co., ltd qw-r502-a75.a 3 a , 1mhz, high efficienc y ? description the utc UC3658 is a high-efficiency 1mhz synchronous step-down dc-dc regulator ic c apable of delivering up to 3a output current. the utc UC3658 operates over a wide input voltage ranging form 3~5.5v and integrate main switch and synchronous switch with very low r ds(on ) to minimize the conduction loss. low output voltage ripple and small external inductor and capacitor sizes are achieved with 1mhz switching provides the system reset function and facilitates the output sequencing design. ? features * low r ds(on) for internal switches (top/bottom) 100m ? /70m ? , 3a * 3~5.5v input voltage range * 1mhz switching frequency minimizes the external components * internal softstart lim its the inrush current *100% dropout operation * output power good indicator * rohs compliant and halogen free * compact and thermally enhanced so8 package with exposed paddle ? ordering information ordering number package packing lead free halogen free UC3658l-sh2-r UC3658g-sh2-r hsop-8 tape reel ? marking information package marking hsop-8 free datasheet http://
UC3658 preliminary cmos ic unisonic technologies co., ltd 2 of 4 www.unisonic.com.tw qw-r502-a75.a ? pin configuration 1 2 3 4 8 7 6 5 nc in lx gnd fb en pg nc gnd ? pin description pin no. pin name description 1, 6 nc no connections 2 in input pin. decouple this pin to gnd pin with at test 1 f ceramic cap 3 lx inductor pin. connect this pi n to the switching node of inductor 4, paddle gnd ground pin 5 fb output feedback pin. connect this pin to the center point of the output resistor divide (as shown in figure 1)to program the output voltage: v out =0.6*(1+r 1 /r 2 ) 7 en enable control. pull high to turn on. do not float 8 pg power good indicator. when the output voltage exceeds 90% of regulation point, it becomes open drain; low otherwise free datasheet http://
UC3658 preliminary cmos ic unisonic technologies co., ltd 3 of 4 www.unisonic.com.tw qw-r502-a75.a ? absolute maximum rating parameter symbol ratings unit supply input voltage v in 6.0 v enable, fb voltage v fb v in +0.6 v junction temperature t j 150 c storage temperature t stg -65~150 c notes: 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 oper ation is not implied. 2. the device is not guaranteed to func tion outside its operating conditions. ? recommended operating conditions parameter symbol ratings unit supply input voltage v in 3 ~ 5.5 v junction temperature t j -40 ~ 125 c ambient temperature t a -40 ~ 85 c ? thermal data parameter symbol ratings unit junction to ambient ja 143 c/w junction to case jc 14 c/w ? electrical characteristics (v in =3.6v, v out =2.5v, l=2.2uh, c out =10uf, t a =25c, i max =1a unless otherwise specified) parameter symbol test conditions min typ max unit input voltage range v in 3 5.5 v shutdown current i shdn en=0 0.1 1 a feedback reference voltage v ref 0.588 0.6 0.612 v fb input current i fb v fb =v in -50 50 na pfet ron r ds ( on ) ,p 0.1 ? neet ron r ds ( on ) ,n 0.07 ? pfet current limit i lim 3.6 a en rising threshold v enh 1.5 v en falling threshold v enl 0.4 v input uvlo threshold v uvlo 2.9 v uvlo hysteresis v hys 0.2 v oscillator frequency f osc i out =100ma 1 mhz min on time 50 ns max duty cycle 100 % thermal shutdown temperature 150 c free datasheet http://
UC3658 preliminary cmos ic unisonic technologies co., ltd 4 of 4 www.unisonic.com.tw qw-r502-a75.a ? typical application circuit in pg gnd en lx fb on/off v in r 3 l r 1 r 2 c 1 (opt.) v out c out figure 1. schematic diagram 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. free datasheet http://
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