The ADP1821 is well suited for a wide range of high power applications, such as DSP and processor core power in telecom, medical imaging, high performance servers, and industrial applications. It operates from a 3.0 V to 5.5 V supply with a power input voltage ranging from 1.0 V to 24 V. The ADP1821 can operate at any frequency between 300 KHz and 1.2 MHz either by synchronizing with an external source or an internally generated, logic controlled clock of 300 KHz or 600 KHz. It includes an adjustable soft start to allow sequencing and quick power-up while preventing input inrush current. Output reverse-current protection at startup prevents excessive output voltage excursions. The adjustable, virtually lossless current-limit scheme reduces external part count and improves efficiency.