Control circuit, control method and switching power supply thereof

A control circuit for generating a switching control signal to control switching operations of a power switch in a power stage circuit, the control circuit comprising:

• a) a first control loop configured to receive a first voltage feedback signal, and to generate a first compensation signal;
• b) a voltage regulating circuit configured to receive an output voltage signal of said power stage circuit, and to generate a second compensation signal according to a difference in said output voltage signal between first and second operating time periods of said power stage circuit, wherein no current is provided to a load of said power stage circuit during said second operating time period;
• and
• c) a control and driving circuit configured to receive said first and second compensation signals and a first sense voltage signal that represents a current through an inductor of said power stage circuit, and to generate a switching control signal in accordance with said first compensation signal when in said first operating time period, and in accordance with said second compensation signal when in said second operating time period.