A bidirectional wide load range multiphase buck/boost converter for differential power processing

Abstract

Series stacking of dc voltage domains to allow power delivery at higher voltages and lower currents has been explored for some time. Differential power processing (DPP) is an integral part of many such applications. DPP benefits from bidirectional converters to process the difference in currents between two consecutive stacked domains to regulate voltages of each domain. In this paper we discuss the importance of having DPP converters with low light load power loss. Then we develop a multiphase buck/boost converter with asymmetric current sharing between phases to achieve good efficiencies over a wide load range. A new light-load (variable frequency, discontinuous conduction mode) control is also developed to improve light load efficiency.