An On-Chip PWM-Based DC-DC Buck Converter Design with High- Efficiency Light Load Mode Operation

Abstract

This paper demonstrates a DC-DC buck converter with a PWM (pulse width modulation) feedback control loop, which can accommodate the range of power supply voltage from VDD to 2.5xVDD. By utilizing HV (high voltage) MOSFETs provided by HV CMOS technologies, a PWM feedback loop, a Dead-time detector, HV driving transistors and a control circuit are all realized on a single chip. The chip area of the proposed design is less than 1.379x0.813 mm 2 , while the power supply range is as wide as 5-14 V. The proposed design is featured with very high conversion efficiency by shutting off an optimal number of power MOSFETs when detecting the light load to prolong the life time of battery-powered devices. Therefore, it can be integrated in a SOC (system-on-chip) to provide multiple supply voltage sources.