Circuit and method of frequency jitter, and application thereof in switched-mode power supply (SMPS)

摘要

The present invention is to provide a frequency jitter circuit and a method for generating frequency jitter. The frequency jitter circuit, comprising: an oscillating circuit, configured to generate an oscillating frequency output signal; a decoding circuit, configured to be controlled by said oscillating frequency output signal for generating several pulse output signals; a delay circuit, through which said oscillating frequency output signal is passed for generating a frequency jitter output signal that is delayed a period of time compared to said oscillating frequency output signal. Application of the invention into switched-mode power supply might reduce EMI average noise in the switched-mode power supply, and smooth energy spectrum density.