Switching converter and control circuit and control method thereof

Abstract

A switching converter and control circuit and control method thereof are disclosed. The switching converter includes a power switch and converts an input voltage to an output voltage. The control circuit includes an input voltage detection circuit, a compensation current generator and a comparison circuit. The input voltage detection circuit generates a first voltage signal indicative of the input voltage and generates a second voltage signal by low-pass filtering the input voltage. The compensation current generator generates a compensation current signal based on the first voltage signal and the second voltage signal. The comparison circuit generates a turning off control signal to control the turning off of the power switch based on the compensation current signal, a current sensing signal indicative of a current flowing through the power switch and a reference signal. The switching converter significantly reduce the overshoot or undershoot of the output voltage when the input voltage changes.

Images