Resonant switched capacitor stacked topology enabling high DC-DC voltage conversion ratios and efficient wide range regulation

This paper presents a stacked-topology resonant switched-capacitor (ResSC) dc-dc converter to achieve a high voltage conversion ratio. The topology can be generalized to any N-to-1 dc-dc conversion application with only a single inductor. Multiphase interleaving can be further employed to improve the ripple cancellation and reduce requirement for bypass capacitors. To enable a wide output range while maintaining high efficiency, a phase shift operation is adopted. The regulation is maintained with frequency modulation. The controller is designed with the aid of current phase compensation in addition to voltage mode control. A prototype of a nominal 4-to-1 two phase interleaved resonant switched capacitor converter has been built and tested. The control and regulation of the output voltage are verified through the experiment. Burst mode is further introduced to improve efficiency at the light load condition.