ver: 1.0 nov 09, 2011 tel: 886-3-5788833 http://www.gmt.com.tw 1 G5617a/G5617b global mixed-mode technology programmable output high-speed step-down controller for notebook computer features ? ultra-high efficiency ? no current-sense resistor (lossless i limit ) ? quasi-pwm with 100ns load-step response ? 1% vout accuracy over line and load ? 0.75v to 3.6v adjustable output range ? dynamic voltage scaling by g0 and g1 inputs ? 4.5v to 24v battery input range ? ovp & uvp ? built-in bst diode ? 1.7ms soft-start ? drives large synchronous-rectifier fets ? power-good indicator ? g0/g1 high active (G5617a) g0/g1 low active (G5617b) applications ? notebook computers ? cpu core supply ? chipset/ram supply as low as 0.75v ? 1.8v and 2.5v i/o supply ? networking power supply general description G5617a/G5617b pwm controller uses constant on-time control scheme to handle wide input/output voltage ratios with ease and provides 100ns ? in- stant-on ? response to load transients while maintaining a relatively constant switching frequency. the G5617a/G5617b achieves high efficiency at a re- duced cost by eliminating the current-sense resistor found in traditional current-mode pwms. efficiency is further enhanced by an ability to drive very large syn- chronous rectifier mosfets. single-stage buck con- version allows these devices to directly step down high-voltage batteries for the highest possible effi- ciency. alternatively, two-stage conversion (stepping down the +5v system supply instead of the battery) at a higher switching frequency allows the minimum pos- sible physical size. the G5617a/G5617b is intended for cpu core, chipset, dram, or other low-voltage supplies as low as 0.75v. it provides four resis- tor-programmable output voltages by g0 and g1 digi- tal inputs. the G5617a/G5617b is available in 16-pin tqfn (3x3) package. ordering information order number marking temp. range package (green) G5617ar41u 5617a -40 c to +85 c tqfn3x3-16 G5617br41u 5617b -40 c to +85 c tqfn3x3-16 note:r4:tqfn3x3-16 1: bonding code u: tape & reel pin configuration G5617a/G5617b tqfn3x3-16 g0 1 2 3 4 12 11 10 9 dh lx ilim vdd 16 15 14 13 dl d1 d0 thermal pad g1 bst en_skip ton out vcc fb pgood 5 6 7 8 17 gnd note: recommend connecting the thermal pad to the ground for excellent power dissipation. G5617a/G5617b tqfn3x3-16 g0 1 2 3 4 12 11 10 9 dh lx ilim vdd 16 15 14 13 dl d1 d0 thermal pad g1 bst en_skip ton out vcc fb pgood 5 6 7 8 17 gnd note: recommend connecting the thermal pad to the ground for excellent power dissipation.
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