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

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