G5640 Global Mixed-mode Technology Inc. 2.5A Buck Converter General Description Features The G5640 is a high efficiency, 2.5A buck converter with a high-side low RDS(ON) switch. It operates from 4.75V to 20V input voltage range, and provides up to 2.5A continuous output current with the output voltage adjustable down to 1.2V. Whenever the load is light, the G5640 automatically change the PWM operation mode to PFM operation to minimize the power consumption. Hence it is suitable for battery-powered devices. 4.75V to 20V Supply Voltage Operating Range Fixed 500kHz Switching Frequency Current-Mode Buck PWM Converter Built-in P-Channel Power MOSFET 2.5A Output Current 1.2V Internal Reference Shutdown Control Thermal-Shutdown and Internal Soft Start Cycle-by-Cycle Current-Limit Short Circuit Protection Under-Voltage Lockout Protection SOP-8 Package It uses a fixed switching frequency up to 500kHz. When a short circuit is detected on the output, the device change switching frequency to 50kHz to protect IC from damage. Applications The G5640 is available in a SOP-8 package. Distributed Power Systems Battery Charger Palmtop Computers, PDAs DSL Modems Ordering Information ORDER NUMBER MARKING TEMP. RANGE PACKAGE (Green) G5640P11U G5640 -40°C to +85°C SOP-8 Note: P1: SOP-8 1: Bonding Code U : Tape & Reel Pin Configuration Typical Application Circuit G5640 VIN 5V~18V CC2 optional G5640 IN 1 8 NC EN 2 7 LX COMP 3 6 GND FB 4 5 10µF OFF ON EN COMP GND CC SOP-8 CC2 optional D1 SS34 R1 VOUT COUT MLCC FB R2 RC G5640 VIN 5V~18V NC L LX IN IN 10µF OFF ON EN COMP CC GND L LX D1 SS34 VOUT R1 0.1µF R2 COUT Electrolytic FB RC VOUT = 1.2V x ( 1 + R1 R2 ) * Refer to Table 1 & Table 2 for Component Selection TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 0.8 May 25, 2010 1