Development of a switched-capacitor DC-DC converter with bidirectional power flow

This brief presents a switched-capacitor dc-dc converter that offers features of voltage step-down, voltage step-up, and bidirectional power flow. Concept of energy transfer is achieved by using two current-controlled bidirectional converter cells, which operate in antiphase. Good regulation capability and continuous input current waveform are other substantial advantages that facilitate practical realization and reduce electromagnetic interference with other circuits and supply networks. State-space averaging technique is applied to study the static and dynamic characteristics. A 20-W, 5-V-9-V prototype has been built and has an overall efficiency of over 80% in all operations.