The MAX1572 is a fixed-frequency, synchronous step-down DC-to-DC converter to power low-voltage microprocessor/DSP cores in portable equipment requiring high efficiency in a limited PC board area. The features are optimized for high efficiency over a wide load range, small external component size, low output ripple, and excellent transient response. The input supply voltage range is from 2.6V to 5.5V, while the output is internally fixed from 0.75V to 2.5V in 50mV increments with a guaranteed output current of 800mA. The high 2MHz switching allows tiny low-cost capacitors and a low-profile inductor, while the power-saving pulse-group mode reduces quiescent current to 48µA (typ) with light loads. To reduce noise and RF interference, the converter can be configured to provide forced-PWM operation.

The MAX1572 includes a low on-resistance internal MOSFET switch and synchronous rectifier to maximize efficiency and minimize external component count. No external diode is needed. Other features include soft-start to eliminate inrush current at startup and a 170ms (min) RESET-bar output to provide power-on/undervoltage reset. The MAX1572 is available in a 12-pin, 4mm x 4mm thin QFN package with exposed paddle.