Dynamic Capacitor Ampere-Second Balance Transient Calculation Modeling Method for Switched-Capacitor Converters

Abstract

Switched-capacitor (SC) converters have drawn more and more attention in recent years due to their unique advantages. The accurate analysis methods will fully determine an SC converter's steady-state and dynamical performance. Proper design of SC converters requires full understanding of all impacts on circuit operation including steady-state and dynamical performance. Some previous modeling methods for SC converters have established a popular static model for SC converters which is composed of an ideal transformer and equivalent output resistance. This paper presents a dynamic capacitor ampere-second balance transient calculation modeling method. The instantaneous state of input voltage, instantaneous state of output voltage, instantaneous state of voltage of flying capacitor, “on time” and “off time,” as well as switching period are all included in the proposed model. The proposed modeling method was applied in both the dual-phase SC converters and the two-switch boosting SC converters. This modeling method was validated by the simulation and experimental results. The proposed model can be used to accurately predict and optimize the performance in the design phase for the low and high power SC converters. Based on the proposed modeling method, the SC converters could be controlled by a variable frequency control method.