General Description
The MAX1733/MAX1734 step-down DC-DC converters deliver over 250mA to outputs as low as 1.25V. These converters use a unique proprietary current-limited control scheme that achieves over 90% efficiency. These devices maintain extremely low quiescent supply current (40µA), and their high 1.2MHz (max) operating frequency permits small, low-cost external components. This combination of features makes the MAX1733/MAX1734 excellent high-efficiency alternatives to linear regulators in space-constrained applications.

Features
♦ 250mA Guaranteed Output Current
♦ Synchronous Rectifier for Over 90% Efficiency
♦ Tiny 5-Pin SOT23 Package
♦ 40µA Quiescent Supply Current
♦ 0.01µA Logic-Controlled Shutdown
♦ Up to 1.2MHz Switching Frequency
♦ Fixed 1.8V or 1.5V Outputs (MAX1734)
♦ Adjustable Output Voltage (MAX1733)
♦ ±1.5% Initial Accuracy
♦ 2.7V to 5.5V Input Range
♦ Soft-Start Limits Startup Current

Applications
    Cellular, PCS, and Cordless Telephones
    PDAs, Palmtops, and Handy-Terminals
    Battery-Powered Equipment