Conv DC-DC Single Step Down 4V to 11.5V 8-Pin SOIC N

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.

• 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