Interleaved switching power supply and control method for the same

A method of controlling an interleaved switching power supply having a plurality of parallel coupled power stage circuits, the method comprising:

• a) generating an output voltage feedback signal from an output voltage of said interleaved switching power supply;
• b) receiving a plurality of switching control signals, and generating an AC ripple signal having a frequency that is N times a switching frequency, wherein N is equal to a number of said plurality of power stage circuits;
• c) generating a superposition signal by adding said output voltage feedback signal with said AC ripple signal;
• d) generating a comparison signal from said superposition signal and a reference voltage;
• e) dividing said comparison signal into a plurality of turn on control signals for controlling turn on of a plurality of main power switches in said plurality of power stage circuits, wherein at least two of said plurality of turn on control signals have a predetermined phase angle therebetween;
• f) generating a current-sharing signal from sampling inductor currents in said plurality of power stage circuits;
• g) generating a plurality of turn off control signals for controlling turn off of said plurality of main power switches in response to said current-sharing signal and said plurality of turn on control signals;
• and
• h) generating said plurality of switching control signals for controlling said plurality of main power switches in response to said plurality of turn on and turn off control signals.

A method of controlling an interleaved switching power supply having a plurality of parallel coupled power stage circuits, the method comprising:

• a) generating an output voltage feedback signal from an output voltage of said interleaved switching power supply;
• b) receiving a plurality of switching control signals, and generating an AC ripple signal having a frequency that is N times a switching frequency, wherein N is equal to a number of said plurality of power stage circuits;
• c) generating a superposition signal by adding said output voltage feedback signal with said AC ripple signal;
• d) generating a comparison signal from said superposition signal and a reference voltage;
• e) dividing said comparison signal into a plurality of turn on control signals for controlling turn on of a plurality of main power switches in said plurality of power stage circuits, wherein at least two of said plurality of turn on control signals have a predetermined phase angle therebetween;
• f) generating a plurality of chopped signals by chopping a voltage source according to a corresponding of said plurality of switching control signals;
• g) generating, by filtering said plurality of chopped signals, a first filtered signal having a phase that matches said inductor current in a corresponding of said plurality of power stage circuits;
• h) generating a second filtered signal by smoothing said first filtered signal;
• and
• i) generating said AC ripple signal from said first and second filtered signals.