The UCC3588 synchronous step-down (Buck) regulator provides accurate high efficiency power conversion. Using few external components, the UCC1588 converts 5V to an adjustable output ranging from 3.5 VDC to 2.1 VDC in 100-mV steps and 2.05 VDC to 1.3 VDC in 50-mV steps with 1% dc system accuracy. A high level of integration and novel design allow this 16-pin controller to provide a complete control solution for today's demanding microcontroller power requirements. Typical applications include on board or VRM based power conversion for Intel Pentium II microprocessors, as well as other processors from a variety of manufacturers. High efficiency is obtained through the use of synchronous rectification. The softstart function provides a controlled ramp up of the system output voltage. Overcurrent circuitry detects a hard (or soft) short on the system output voltage and invokes a timed softstart/shutdown cycle to reduce the PWM controller on time to 5%.