Patent ID: 11962247
Assignee: RICHTEK TECHNOLOGY CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 10:
11. A control method for controlling a resonant half-bridge flyback power converter, wherein the resonant half-bridge flyback power converter includes a first transistor and a second transistor which are configured to 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; the resonant half-bridge flyback power converter comprising:
switching the transformer with periodical switching cycles to generate an output voltage by switching the half-bridge circuit;
generating a skipping cycle period when an output power corresponding to the output voltage is lower than a predetermined threshold;
wherein the switch-on of the first transistor magnetizes the transformer; the switch-on of the second transistor achieves a resonant cycle or achieves ZVS for the first transistor;
wherein a resonant pulse of the second driving signal is skipped during the skipping cycle period; wherein the skipping cycle period is increased in response to the decrease of the output power;
wherein the resonant cycle further includes an extended ZVS period for achieving ZVS of the first transistor.