Switching converter, and control method and control circuit thereof

A control circuit of a switching converter, the switching converter converts a DC input voltage into a DC output voltage, the control circuit comprising:

• a compensation module, configured to generate a command signal is proportional with the DC output voltage, and to generate a ramp signal according to the command signal, wherein the command signal is proportional with the DC output voltage, so that the slope of the ramp signal is related to the amplitude of the DC output voltage;
• a comparator, configured to compare a first superimposed signal related to the DC output voltage with a second superimposed signal related to the ramp signal and an error signal of the DC output voltage, so that an intermediate signal is obtained to generate a set signal;
• a first RS flip-flop, configured to generate a pulse width modulation signal in accordance with the set signal and a reset signal, obtain a constant on time in accordance with the reset signal, and obtain an off time related to the DC output voltage in accordance with the set signal;
• and
• a driving module, configured to convert the pulse width modulation signal into a switching control signal,
• wherein the compensation module adaptively adjusts the slope of the ramp signal in accordance with DC output voltage.