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. Applications * 5V to 3.3V Conversion * 9V Battery to 5V, 3.3V, or 3V Conversion * High-Efficiency Linear Regulator Replacement * Portable Instruments and Handy-Terminals * 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 https://elecena.pl/product/22331274/5v-3-3v-3v-adjustable-high-efficiency-low-i-step-down-dc-dc-converters 2022-12-28 https://elecena.pl/product/22331274/5v-3-3v-3v-adjustable-high-efficiency-low-i-step-down-dc-dc-converters 2025-01-22