RC5051

www.fairchildsemi.com RC5051 Programmable Synchronous DC-DC Controller for Low Voltage Microprocessors Features Programmable output from 1.3V to 3.5V using an integrated 5-bit DAC 85% efficiency typical Adjustable operation from 80KHz to 1MHz Integrated Power Good and Enable functions Overvoltage protection Overcurrent protection Drives N-channel MOSFETs 20 pin SOIC package Meets Intel Pentium II specifications using minimum number of external components Description The RC5051 is a synchronous mode DC-DC controller IC which provides an accurate, programmable output voltage for all Pentium II CPU applications. The RC5051 uses a 5-bit D/A converter to program the output voltage from 1.3V to 3.5V. The RC5051 uses a high level of integration to deliver load currents in excess of 19A from a 5V source with minimal external circuitry. Synchronous-mode operation offers optimum efficiency over the entire specified output voltage range, and the internal oscillator can be programmed from 80KHz to 1MHz for additional flexibility in choosing external components. An on-board precision low TC reference achieves tight tolerance voltage regulation without expensive external components. The RC5051 also offers integrated functions including Power Good, Output Enable, over-voltage protection and current limiting. Applications Power supply for Pentium® II VRM for Pentium II processor Programmable step-down power supply Block Diagram +12V RC5051 1 – + +5V 5 4 OSC – + 13 1...