ver: 0.2 jan 13, 2010 tel: 886-3-5788833 http://www.gmt.com.tw 1 G5217 global mixed-mode technology inc. 24v input voltage-mode buck pwm controller features ? drives two n-channel mosfets ? operates at 5v to 24v supply voltage ? internal bootstrap diode circuit ? voltage-mode pwm control ? fast transient response ? 0.8v, 2% accuracy reference voltage ? internal soft start ? constant 300khz switching frequency ? over-current fault monitors by using low-side mosfet r ds(on) ? output under-voltage protection applications ? 16v to 30v input high power dc-dc regulators ? low-voltage distributed power supplies general description the G5217 provides complete control and protection for a dc-dc converter for high power applications. it is designed to drive two n-channel mosfets in a syn- chronous-rectified buck topology. the G5217 inte- grates all of the control, bootstrap diode and protection functions into a single package. the G5217 provides simple, single feedback loop, voltage-mode control with fast transient response. it includes a 300khz free-running triangle-wave oscilla- tor. the error amplifier features a 15mhz gain-band- width product which provides high converter band- width for fast transient performance. the resulting pwm duty ratio ranges from 0% to 80%. the refer- ence voltage is 0.8v, 2% accuracy. the G5217 has internal soft start and executes cy- cle-by-cycle current limit during soft start interval. the G5217 monitors the current by using the r ds(on) of the low-side mosfet which eliminates the need for a current sensing resistor. the under-voltage protection function monitors voltage at fb pin. the over-current and under-voltage events after soft-start interval trig- ger hiccup mode protection. ordering information order number marking temp. range package (green) G5217p11u g 5217 -40 c~ +85 c sop-8 note: p1: sop-8 1: bonding code u: tape & reel pin configuration typical application circuit G5217 lgate 8 6 5 1 2 3 4 ugate lx gnd boot vcc ocset fb sop-8 7 boot shdn ugate 3 h ocset fb lgate gnd vcc 5v ~ 24v G5217 0.1 f 2000 f 10nf 10 4.7 f 220 f 620 39 r ocset lx v o =13.5v G5217 lgate 8 6 5 1 2 3 4 ugate lx gnd boot vcc ocset fb sop-8 7 boot shdn ugate 3 h ocset fb lgate gnd vcc 5v ~ 24v G5217 0.1 f 2000 f 10nf 10 4.7 f 220 f 620 39 r ocset lx v o =13.5v
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