Controller and controlling method for power converter

摘要

A controller for a power converter is provided. The controller includes a sense current integrating circuit, a reference current integrating circuit and a drive signal generation circuit. The sense current integrating circuit performs an integrating operation to a sense current representative of a conduction current flowing through a power switch of the power converter and thereby outputs a first integrating result. The reference current integrating circuit performs another integrating operation to a reference current and thereby outputs a second integrating result. The drive signal generation circuit determines a switching period of the power switch according to a status of an output voltage of the power converter cooperative with a relative magnitude relationship between the first integrating result and the second integrating circuit. Furthermore, a controlling method for such power converter also is provided.