G5333A Global Mixed-mode Technology High Efficiency 4A Synchronous Buck Converter Features General Description G5333A is a 4A, synchronous DC/DC buck converter with integrated 30mΩ N-channel high-side MOSFET and 30mΩ 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 G5333A 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 10mA for internal circuits. The G5333A is intended for the power supply as low as 0.9V. The G5333A is available in QFN3X3-21 package. Ultra-High Efficiency Low Quiescent Current of 30µA Integrated 30mΩ at V5V=5V N-Channel MOSFET for Low Side Integrated 30mΩ at V5V=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 0.9V to 5.5V Adjustable Output Range 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, 10mA Linear Regulator Applications Networking Power Supply I/O Supply Ordering Information ORDER NUMBER MARKING TEMP. RANGE PACKAGE (Green) G5333AQP1U 5333A -40°C to +85°C QFN3X3-21 AGND V5V TON BST V+ V+ V+ V+ 19 18 17 16 15 21 FB Pin Configuration 20 Note: QP: QFN3X3-21 1: Bonding Code U : Tape & Reel 14 V+ 1 V+ AGND 2 13 V+ PGOOD 3 EN 4 PGND 5 PGND 6 9 10 11 12 PGND PGND PGND 8 LX LX 7 LX LX G5333A QFN3X3-21 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 Aug 12, 2013 1