Constant on-time variable frequency one-cycle control for switched-capacitor converter

Abstract

The constant-on time variable frequency one-cycle control is adapted for switched-capacitor converter in this paper. Based on the capacitor ampere-second balance principle, mathematical derivation of control model is provided. Simulation and experiment results show that the external disturbances can be immediately rejected by adjusting the switching period while maintaining the switch “on time”, resulting in a variable frequency control. Compared with conventional constant frequency control method, the dynamic response speed is significantly improved with minimum overshot at the transient time. The constant on-time variable frequency OCC control method can be used in a wide power range and different types of switched-capacitor converters.