UC Irvine

This thesis presents a new dual resonant switched-capacitor converter topology that inverts the polarity of input voltages and can regulate the gain continuously between 0 and –1, even at light load operation. A literature review on the development and improvement of switched-capacitor converters over the years is presented in Chapter 1. The switched capacitor in the presented converter is charged and discharged through resonant inductors, eliminating large current spikes and charge sharing losses associated with pure switched-capacitor converters. This resonance allows for ZCS turn-on of all switches and ZCS turn-off of all diodes. Chapter 2 presents a detailed analysis of the dual resonant switched-capacitor polarity inverter, in which a voltage gain curve in four distinct operating modes is provided, along with a detailed discussion of boundary conditions between modes. Voltage and current stresses of all components are analyzed, and design guidelines for designing the presented converter from a specified input voltage, output voltage, and output power are presented. In addition, a regenerative snubber to eliminate undesirable parasitic ringing is provided. An 80V to –35V ~ –72V open loop prototype with peak efficiency 97.0% and maximum power 120W was built to verify the operation of the converter, and the experimental results from this prototype are presented in Chapter 3. Finally, in Chapter 4, several extensions of the topology are presented to reduce the step-down ratio of the converter or to apply the topology to step-up applications.