ver: 1.6 nov 03, 2011 tel: 886-3-5788833 http://www.gmt.com.tw 1 G5108 global mixed-mode technology low-noise step-up dc-dc converter features ? 90% efficiency ? adjustable output from v in to 20v ? 0.2 , 24v power mosfet ? cycle-by-cycle 2a current limit ? 2.5v to 5.5v input range ? 600khz/1.2mhz switching frequency ? msop-8, tdfn3x3-8 package applications ? lcd displays ? portable applications ? hand-held devices general description the G5108 boost converter in corporate high-per- formance, current-mode, frequency selectable pulse width modulation (pwm) circuitry with a built-in 0.2 n-channel mosfet to provide a highly efficient regu- lator. high switching frequency allows easy filtering and faster loop performance. an external compensation pin provides the user flexibility in determining loop dy- namics, allowing the use of small, low esr ceramic output capacitors. the device can produce an output voltage as high as 20v. user programmed soft-start with an external capacitor determines the input current ramp rate. the G5108 is available in a space-saving msop-8 and tdfn3x3-8 package. ordering information order number marking temp. range package (green) G5108p8u G5108 -40 c ~ +85 c msop-8 G5108rdu 5108 -40 c ~ +85 c tdfn3x3-8 note: p8: msop-8 rd:tdfn3x3-8 u: tape & reel pin configuration typical application circuit 8v 200ma vcc sw shdn comp gnd l1 v in 2.5v to 5.5v fb 10nf 4.7 h~10 h c1 22 f fsl ss on off 600khz 1.2mhz 24k c c 2.2nf c2 22 f r1 r2 tdfn3x3-8 1 2 3 4 8 7 6 5 thermal pad G5108 comp msop-8 G5108 ss fsl vcc sw fb shdn gnd 1 2 3 4 8 7 6 5 comp fb shdn gnd ss fsl vcc sw v out v out =1.24 x (1+ r1 r2 ) note: recommend connecting the thermal pad to the ground for excellent power dissipation. r c 3 7 8 1 2 4 5 6 8v 200ma vcc sw shdn comp gnd l1 v in 2.5v to 5.5v fb 10nf 4.7 h~10 h c1 22 f fsl ss on off 600khz 1.2mhz 24k c c 2.2nf c2 22 f r1 r2 tdfn3x3-8 1 2 3 4 8 7 6 5 thermal pad G5108 comp msop-8 G5108 ss fsl vcc sw fb shdn gnd 1 2 3 4 8 7 6 5 comp fb shdn gnd ss fsl vcc sw v out v out =1.24 x (1+ r1 r2 ) note: recommend connecting the thermal pad to the ground for excellent power dissipation. r c 3 7 8 1 2 4 5 6
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