MAX8625A

19-1006; Rev 0; 3/08 High-Efficiency, Seamless Transition, Step-Up/Down DC-DC Converter General Description The MAX8625A PWM step-up/down regulator is intended to power digital logic, hard disk drives, motors, and other loads in portable, battery-powered devices such as PDAs, cell phones, digital still cameras (DSCs), and MP3 players. The MAX8625A provides either a fixed 3.3V or adjustable output voltage (1.25V to 4V) at up to 0.8A from a 2.5V to 5.5V input. The MAX8625A utilizes a 2A peak current limit. Maxim’s proprietary H-bridge topology* provides a seamless transition through all operating modes without the glitches commonly seen with other devices. Four internal MOSFETs (two switches and two synchronous rectifiers) with internal compensation minimize external www.DataSheet4U.com components. A SKIP input selects a low-noise, fixedfrequency PWM mode, or a high-efficiency skip mode where the converter automatically switches to PFM mode under light loads for best light-load efficiency. The internal oscillator operates at 1MHz to allow for a small external inductor and capacitors. The MAX8625A features current-limit circuitry that shuts down the IC in the event of an output overload. In addition, soft-start circuitry reduces inrush current during startup. The IC also features True ShutdownTM, which disconnects the output from the input when the IC is disabled. The MAX8625A is available in a 3mm x 3mm, 14-pin TDFN package. ♦ ♦ ♦ ♦ Features Four Internal MOSFET True H-Bridge...