
Maxim Integrated
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