MAX639, MAX640, MAX653 5V/3.3V/3V Adjustable, High-Efficiency, Low-IQ, Step-Down DC-DC Converters

Low Supply Current, High-Efficiency Over Wide Load Range

Status

Active: In Production.

Description

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The MAX639/MAX640/MAX653 step-down switching regulators provide high efficiency over a wide range of load currents, delivering up to 225mA. A current-limiting pulse-frequency-modulated (PFM) control scheme gives the devices the benefits of pulse-width-modulated (PWM) converters (high efficiency at heavy loads), while using only 10µA of supply current (vs. 2mA to 10mA for PWM converters). The result is high efficiency over a wide range of loads.

The MAX639/MAX640/MAX653 input range is 4V to 11.5V, and the devices provide lower preset output voltages of 5V, 3.3V, and 3V, respectively. Or, the output can be user-adjusted to any voltage from 1.3V to the input voltage.

The MAX639/MAX640/MAX653 have an internal 1A power MOSFET switch, making them ideal for minimum-component, low- and medium-power applications. For increased output drive capability, use the MAX649/MAX651/MAX652 step-down controllers, which drive an external P-channel FET to deliver up to 5W.

Key Features		Applications/Uses
High Efficiency for a Wide Range of Load Currents 10µA Quiescent Current Output Currents Up to 225mA Preset or Adjustable Output Voltage: 5.0V (MAX639) 3.3V (MAX640) 3.0V (MAX653) Low-Battery Detection Comparator Current-Limiting PFM Control Scheme		5V to 3.3V Conversion 9V Battery to 5V, 3.3V, or 3V Conversion High-Efficiency Linear Regulator Replacement Portable Instruments and Handy-Terminals