HARMONIC CONTROL METHOD AND CIRCUIT FOR FLYBACK SWITCHING POWER SUPPLY

摘要

In one embodiment, harmonic control method for a flyback switching power supply, can include: (i) generating a sense voltage signal based on an output signal of the flyback switching power supply; (ii) generating a first compensation signal by determining and compensating an error between the sense voltage signal and a reference voltage; (iii) generating a second compensation signal by regulating the first compensation signal based on a duty cycle of a main power switch in the flyback switching power supply; and (iv) generating a control signal based on the second compensation signal and a triangular wave signal, to control the main power switch such that the output signal is substantially constant and an input current follows a waveform variation of an input voltage of the flyback switching power supply.

主权项

1. A harmonic control method for a flyback switching power supply, the method comprising:
a) generating a sense voltage signal based on an output signal of said flyback switching power supply; b) generating a first compensation signal by determining and compensating an error between said sense voltage signal and a reference voltage; c) generating a second compensation signal by regulating said first compensation signal based on a duty cycle of a main power switch in said flyback switching power supply; and d) generating a control signal based on said second compensation signal and a triangular wave signal, to control said main power switch such that said output signal is substantially constant and an input current follows a waveform variation of an input voltage of said flyback switching power supply.