The CS51031 is a switching controller for use in DC-DC converters. It can be used in the buck topology with a minimum number of external components. The CS51031 consists of a VCC monitor for control-ling the state of the device, 1.0A power driver for controlling the gate of a discrete P-channel transistor, fixed frequency oscillator, short circuit protection timer, programmable soft start, precision reference, fast output voltage monitoring comparator, and output stage driver logic with latch. The high frequency oscillator allows the use of small inductors and output capacitors, minimizing PC board area and systems cost. The programmable soft start reduces current surges at start up. The short circuit protection timer significantly reduces the duty cycle to approximately 1/30 of its cycle during short circuit conditions. The CS51031 is available in 8 Lead SO plastic packages.