G5385A Global Mixed-mode Technology High Efficiency 8A Synchronous Buck Converter Features General Description G5385A is a 8A, synchronous DC/DC buck converter with integrated 30mΩ N-channel high-side MOSFET and 15mΩ N-channel low-side MOSFET. It uses constant on-time control scheme to handle wide input/output voltage ratios with ease and provides 100ns “instant-on” response to load transients while maintaining a relatively constant switching frequency. The G5385A achieves high efficiency at a reduced cost by eliminating the current-sense resistor found in traditional current-mode PWMs. Single-stage buck conversion allows these devices to directly step down high-voltage batteries for the highest possible efficiency. The G5385A is intended for the power supply of Notebook Computer, or other low-voltage supplies as low as 0.75V. The G5385A is available in QFN4X4-28 package. Ultra-High Efficiency Low Quiescent Current of 60µA Integrated 15mΩ at VCC=5V N-Channel MOSFET for Low Side Integrated 30mΩ at VCC=5V N-Channel MOSFET for High Side No Current-Sense Resistor (Lossless ILIMIT) Quasi-PWM with 100ns Load-Step Response 1% VOUT Accuracy Over Line and Load Programmable Switching Frequency 0.75V to 3.6V Adjustable Output Range 3V to 28V Adapter or Battery Input Range Integrated Boost Switch OVP & UVP Over Temperature Protection (non-latch) 2ms Soft-Start Power-Good Indicator Applications Notebook Computers I/O Supply Chipset/RAM Supply as Low as 0.75V Networking Power Supply Ordering Information ORDER NUMBER MARKING TEMP. RANGE PACKAGE (Green) G5385AQN1U 5385A -40°C to +85°C QFN4X4-28 Note: QN: QFN4X4-28 1: Bonding Code U: Tape & Reel 6 LX 7 LX 8 V+ 19 V+ 18 V+ 17 V+ VCC AGND FB TON BST NC NC LX 27 26 25 24 23 22 21 LX LX PGND 16 LX PGND 15 5 PGND 14 NC PGND 13 4 PGND 12 PGND V+ PGND 11 3 9 V+ EN 20 10 1 2 LX PGOOD 28 Pin Configuration G5385A QFN4X4-28 Note: Recommend connecting the Thermal Pad to the Ground for excellent power dissipation. TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 0.2 Aug 22, 2013 1