Resonant flyback power converter and switching control circuit and method thereof

A resonant flyback power converter, comprising:

• a first transistor and a second transistor which form a half-bridge circuit;
• a transformer and a resonant capacitor which are connected in series and are coupled to the half-bridge circuit;
• and
• a switching control circuit configured to operably generate a first driving signal and a second driving signal to control the first transistor and the second transistor respectively for switching the transformer and the resonant capacitor to generate an output voltage;
• wherein the switching control circuit is configured to turn on the first transistor to generate a first current to magnetize the transformer and charge the resonant capacitor, and is configured to turn on the second transistor to generate a second current to discharge the resonant capacitor;
• wherein during a power-on period of the resonant flyback power converter, the switching control circuit generates a plurality of short-pulses of the second driving signal to turn on the second transistor for discharging the resonant capacitor.

A method for use in controlling a resonant flyback power converter which includes a first transistor and a second transistor which form a half-bridge circuit;

• and a transformer and a resonant capacitor which are connected in series and are coupled to the half-bridge circuit, wherein the half-bridge circuit is configured to switch the transformer and the resonant capacitor to generate an output voltage;
• wherein the method comprises:
• generating a first driving signal which is configured to turn on the first transistor to generate a first current to magnetize the transformer and charge the resonant capacitor;
• and
• generating a second driving signal which is configured to turn on the second transistor to generate a second current to discharge the resonant capacitor;
• wherein during a power-on period of the resonant flyback power converter, the second driving signal includes a plurality of short-pulses configured to turn on the second transistor for discharging the resonant capacitor.