General Description
The MAX1705/MAX1706 are high-efficiency, low-noise, step-up DC-DC converters with an auxiliary linearregulator output. These devices are intended for use in battery-powered wireless applications. They use a synchronous rectifier pulse-width-modulation (PWM) boost topology to generate 2.5V to 5.5V outputs from battery inputs, such as 1 to 3 NiCd/NiMH cells or 1 Li-Ion cell. The MAX1705 has an internal 1A n-channel MOSFET switch. The MAX1706 has a 0.5A switch. Both devices also have a built-in low-dropout linear regulator that delivers up to 200mA.

Features
♦ Up to 96% Efficiency
♦ 1.1VIN Guaranteed Startup
♦ Up to 850mA Output (MAX1705)
♦ Step-Up Output (2.5V to 5.5V Adjustable)
♦ Linear Regulator (1.25V to 5.0V Adjustable)
♦ PWM/PFM Synchronous-Rectified Topology
♦ 300kHz PWM Mode or Synchronizable
♦ 1µA Shutdown Mode
♦ Voltage Monitor
♦ Pushbutton On/Off Control

Applications
    Digital Cordless Phones
    PCS Phones
    Personal Communicators
    Wireless Handsets
    Palmtop Computers
    Two-Way Pagers
    Handheld Instruments