Constant On-Time Variable Frequency Control for a Novel Switched-Capacitor Converter

摘要

Due to the requirement for high power density and high integration, the development of traditional inductive switching power converter has encountered bottlenecks. Switch-capacitor (SC) converter is the development tendency for the DC-DC converter. This paper proposed a novel two-stage SC converter. It is designed to convince the flying capacitors sustain lower voltage stress. Meanwhile, the control method adopts a constant “on-time” of the switches that is less than the time constant τ of charging circuit. It does not need to adjust duty-ratio to control output power. The simulation results show that the control method could reject external interference of the two-stage SC converter immediately. The conclusions can be can be made from simulation results that the constant on-time variable frequency (COTVF) control method could improve dynamic response speed which enable the converter works in a wide range.