FREQUENCY JITTERING CIRCUIT, METHOD AND APPLICATION THEREOF IN SWITCH POWER SUPPLY

摘要

A frequency jittering circuit and a method for generating frequency jitter. The frequency jittering circuit(100) comprises: an oscillating circuit(101) which generates an oscillation frequency output signal(201); a decoding circuit(102), which is controlled by the oscillation frequency output signal to generate pulse output signals(202); and a delay circuit(103), via which the oscillation frequency output signal generates a frequency jittering output signal(203), wherein the frequency jittering output signal is delayed for a period of time as compared to the oscillation frequency output signal, and the pulse output signals control the delay time of the frequency jittering output signal. The frequency jittering circuit can be applied in a switch power supply to reduce the EMI average noise of the switch power supply and realize the planarization of energy spectrum density.