G5309 Global Mixed-mode Technology High Efficiency 10A Synchronous Buck Converter Features General Description G5309 is a 10A, synchronous DC/DC buck converter with integrated 20mΩ N-channel high-side MOSFET and 8.5mΩ 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 G5309 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 built-in 5V LDO supports 20mA for internal circuits. The G5309 is intended for the main power supply of LCD TV, Notebook Computer, or other low-voltage supplies as low as 0.75V. The G5309 is available in QFN4X4-28 and QFN5X5-32 package. Ultra-High Efficiency Integrated 8.5mΩ at Vcc=5V N-Channel MOSFET for Low Side Integrated 20mΩ 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 Adjustable Output Range from 0.75V 4.5V to 28V Adapter or Battery Input Range Integrated Boost Switch OVP & UVP Over Temperature Protection (non-latch) 3.3ms Soft-Start Power-Good Indicator Fixed 5V, 20mA Linear Regulator Applications LCD Monitor/LCD TV 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) G5309QN1U G5309QA1U 5309 5309 -40°C to +85°C -40°C to +85°C QFN4X4-28 QFN5X5-32 Note: QN: QFN4X4-28 1: Bonding Code U : Tape & Reel QA: QFN5X5-32 7 LX 8 16 PGND LX 17 PGND 15 18 PGND 7 8 14 LX PGND PGND 16 PGND 15 PGND 14 LX 13 21 LX V+ 12 BST NC 22 6 AGND PGND EN 23 LX LX PGND 13 25 NC PGND PGND 5 PGND 12 26 BST PGND V+ 6 LX 10 28 TON PGND 19 17 LX PGND 11 27 EN V+ 20 3 LX 9 29 OUT 21 2 V5V 5 LX 30 VCC V+ 4 AGND V+ LX 31 FB TON 24 32 PGOOD V+ 22 V+ 18 PGND 4 23 19 11 PGND V+ AGND 1 PGND 3 ILIM 9 2 V5V V+ V+ 10 AGND 24 20 LX VCC OUT 25 FB 27 26 PGOOD 1 LX ILIM 28 Pin Configuration G5309 QFN5X5-32 G5309 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: 0.7 Apr 01, 2013 1