AC-DC switching power converters with frequency variation in response to load changes

摘要

A method of operating a switching power converter having at least one power switch controlled by a drive signal having a switching frequency is disclosed. The method includes monitoring an output power of the switching power converter, determining whether the output power has decreased below a threshold level and, in response to the output power decreasing below the threshold level, changing the switching frequency of the drive signal from a first switching frequency to a second switching frequency when an operating condition of the switching power converter is satisfied. Also disclosed are controllers and switching power converters (including PFC converters).