PFM and PWM Hybrid Mode Control Strategy for Switching Power Supply and Its Implementation

A PFM and PWM hybrid control strategy for high frequency switching power supply is designed in the article. Power supply working in heavy load mode uses PWM, and power supply at startup or working in light load mode uses PFM. The TIDM-PSFB-DCDC dc regulated power supply produced by TI company is used for experimental verification in hybrid control model. Programming by the STMS320F28335 chip goes on the hardware implementation of control strategy, and a detailed introduction and key statements of the procedure are given. Through the final experimental waveform, the power supply can work smoothly under the mixed control mode, and working conditions of heavy load and light load can be distinguished, and which improves the power supply’s working efficiency.