24V, 600mA Internal Switch, 100% Duty Cycle, Step-Down Converter

The MAX1776 high-efficiency step-down converter provides an adjustable output voltage from 1.25V to VIN from supply voltages as high as 24V. An internal current-limited 0.4Ω MOSFET delivers load currents up to 600mA. Operation to 100% duty cycle minimizes dropout voltage (240mV at 600mA).

The MAX1776 has a low 15µA quiescent current to improve light-load efficiency and conserve battery life. The device draws only 3µA while in shutdown.

High switching frequencies (up to 200kHz) allow the use of tiny surface-mount inductors and output capacitors. The MAX1776 is available in an 8-pin µMAX package, which uses half the space of an 8-pin SO. For increased output drive capability, use the MAX1626/ MAX1627 step-down controllers, which drive an external P-channel MOSFET to deliver up to 20W.

Applications

* Distributed Power Systems * Handheld Devices * Keep-Alive Supplies * Notebook Computers

* Fixed 5V or Adjustable Output

* 4.5V to 24V Input Voltage Range

* Up to 600mA Output Current

* Internal 0.4Ω P-Channel MOSFET

* Efficiency Over 95%

* 15µA Quiescent Supply Current

* 3µA Shutdown Current

* 100% Maximum Duty Cycle for Low Dropout

* Current-Limited Architecture

* Thermal Shutdown

* Small 8-µMAX Package