A Brief Discussion of Two Stability Improvement Methods for Wide-Operation-Range Flyback Converter With Peak-Current-Mode Control at Variable Frequency

Recently, a flyback converter with universal serial bus power delivery (USB-PD) specification is widely used in low-power adaptor application. However, the wide output-voltage-range operation of USB-PD makes the stability issue of the flyback converter more severe. This paper provides a brief discussion of two stability improvement methods for the peak-current-mode-controlled flyback converter at variable frequency and completely interprets those detailed techniques. Simulation validates the performances of the two methods. Furthermore, a control circuit and a flyback converter are built for experimental validation of the two stability improvement methods. Finally, some comments are also summarized.