G5338 Global Mixed-mode Technology High-Speed Step-Down Controller Features General Description G5338 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 G5338 achieves high efficiency at a reduced cost by eliminating the current-sense resistor found in traditional current-mode PWMs. Efficiency is further enhanced by an ability to drive very large synchronous rectifier MOSFETs. Single-stage buck conversion allows these devices to directly step down high-voltage batteries for the highest possible efficiency. The noiseless pulse-skipping mode setting maintains the switching frequency above 25kHz to eliminates the audio noise. The G5338 is intended for CPU core, chipset, DRAM, or other low-voltage supplies as low as 0.5V. The G5338 is available in TQFN2X2-12 package. Ultra-High Efficiency 4700ppm/°C RDS(ON) Current Sensing ( without Current-Sense Resistor ) Quasi-PWM with 100ns Load-Step Response Built in 1% 0.5V Reference Voltage 0.5V to 3.3V Adjustable Output Range 4.5V to 28V Battery Input Range Integrated Boost Diode OVP & UVP 1.5ms Voltage Servo Soft-Start Drives Large Synchronous-Rectifier FETs Power-Good Indicator Thermal Shutdown (Non-latch) Applications Notebook Computers CPU Core Supply I/O Supply Chipset/RAM Supply as Low as 0.5V Ordering Information ORDER NUMBER MARKING TEMP. RANGE PACKAGE (Green) G5338K71U 5338 -40°C to +85°C TQFN2X2-12 Note: K7: TQFN2X2-12 1: Bonding Code U : Tape & Reel TON ILIM 11 10 12 GND Pin Configuration 2 Thermal Pad 8 EN DH 3 7 MODE 6 LX FB PGOOD 5 9 VCC 13 GND 4 1 BST DL G5338 TQFN2X2-12 TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 0.4 May 03, 2012 1