G5380B Global Mixed-mode Technology High Efficiency 8A Synchronous Buck Converter for 3.3V System Power Features General Description G5380B is a 8A, synchronous DC/DC buck converter with integrated 20mΩ N-channel high-side MOSFET and 17mΩ 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 G5380B 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 3.3V LDO supports 80mA for internal circuit with automatic bootstrapping to DC/DC converter output. The G5380B is intended for the 5V system power supply of Notebook Computer. The G5380B is available in QFN4X4-28 package. Ultra-High Efficiency Low Quiescent Current of 40µA Integrated 17mΩ 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 3.0V to 3.6V Adjustable Output Range 5.5V to 28V Adapter or Battery Input Range Noiseless Pulse-skipping Mode (25kHz min) VCLK Output Integrated Boost Switch OVP & UVP Over Temperature Protection (non-latch) 3.3ms Soft-Start Power-Good Indicator Fixed 3.3V, 80mA Bootstrapped Linear Regulator Applications Notebook Computers I/O Supply Networking Power Supply Ordering Information OUT TON BST 22 21 LDO3 ON3 ENL 28 27 Pin Configuration 24 QFN4X4-28 23 -40°C to +85°C PGOOD 5380B G5380BQN1U Note:QN: QFN4X4-28 1: Bonding Code U : Tape & Reel FB PACKAGE (Green) 26 TEMP. RANGE 25 MARKING AGND 1 20 V+ V+ 2 19 V+ VCC 3 VCLK 4 PGND 5 LX 6 LX 7 LX 8 V+ 18 V+ 17 V+ PGND 16 PGND 15 PGND 14 PGND 13 11 PGND 12 PGND 9 LX 10 LX LX ORDER NUMBER G5380B 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: 0.3 Oct 21, 2013 1