Development of switched-capacitor-based DC/DC converter with bi-directional power flow

This paper presents the development of a switched-capacitor (SC)-based DC/DC converter, which can perform bidirectional power flow. Features of voltage step down, step-up, and bi-directional power flow are integrated into a single circuit. The concept of energy transfer is achieved by using two bi-directional SC converter cells that are operating in anti-phase. Good regulation capability and continuous input current waveform are the substantial advantages of the proposed converter for facilitating practical realization and reducing electromagnetic interference with the supply network and other circuits. The steady-state characteristic of the converter is studied by a state-space averaging technique. A prototype converter operating with 5 V/9 V and rated power 20 W has been built. The overall efficiency, which includes the power consumption of the driving circuit, is over 80% in both step-down and step-up operations