General Description

The MAX1947 is a compact, high-efficiency, step-up DC-DC converter that regulates output voltages from 1.8V to 3.3V to power µP/DSP cores, memory, and I/O rails in 1- and 2-cell alkaline/NiMH/NiCd battery-powered systems. It features an internal 800mA switch and synchronous rectifier to achieve up to 94 efficiency and to eliminate the need for an external Schottky diode.

Features

♦ Low Input (0.7V) and Output (1.8V) Voltage

   Capability

♦ Internal Synchronous Rectifier

♦ High 94 Efficiency

♦ Fixed Output Voltages: 1.8V, 2.5V, 3V, and 3.3V

♦ Up to 2MHz Switching Allows Small External

   Components and Low Output Ripple

♦ Automatic Pulse Skipping at Light Loads for

   Extended Battery Life

♦ Low 70µA (typ) Operating Supply Current

   (Measured at OUT)

♦ Low 2µA Logic-Controlled Shutdown

♦ True Shutdown Fully Discharges Output to Ground

♦ Uses Only Small Ceramic Capacitors

♦ 75ms RESET Output Flag

Applications

   MP3 Players, Pagers, and CD Players

   PDAs and Organizers

   Digital Still Cameras

   Cordless Phones

   Wireless Mice/Keyboards

   Portable Medical Equipment

   Other Battery-Powered Systems