An Energy-Efficient Buck-Boost Converter for Mobile Applications

Abstract

In this paper, a single-mode DC-DC Buck-Boost converter using a flying -capacitor is proposed. Since existing DC-DC Buck -Boost Converter has discontinuous output delivery current, DC component of the inductor current is always larger than the load current. This characteristic of the load current increases conduction loss that occurs in the series parasitic resistance (DCR) of the inductor and causes a decrease in the efficiency of the converter. The proposed Buck-Boost Converter secures the characteristics of continuous output delivery current based on Buck operation of LC filtering the switching node voltage. The DC component of the inductor current is always equal to the load current, and total conduction loss can be reduced by designing the number of resistance components in series with the inductor to be one during switching period. The proposed Buck-Boost Converter is manufactured by 180 nm BCDMOS process, and the output voltage can be regulated to 3.3V operating in a single mode with variable input voltages of 2.7 V to 4.2 V. It has a load current range of up to 1 A and uses the PWM Voltage Mode Control method.