Steady-state characteristics of switched-capacitor electronic converters

By performing a detailed analysis of switching-mode power supplies based on switched-capacitor circuits, their fundamental steady-state characteristics are found. A few basic step-down and step-up converters are considered. No approximations, such as averaging techniques, are required. The on-resistances of the transistors, forward voltages of the diodes and equivalent-series resistances of capacitors are taken into account. Design-oriented formulas of the DC voltage ratio, efficiency and output voltage ripple are determined. For a required input-to-output voltage ratio, trade-offs allowing for the best possible efficiency, the smallest possible ripple and the best possible Line and load regulation give the design values of the number of capacitors in the switched-capacitor circuit, of their capacitances and of the switching frequency.