Patent ID: 11929669
Assignee: INVENTCHIP TECHNOLOGY CO., LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  G  Y | IPC G  H

Claim 18:
19. A controller comprising:
a plurality of function units electrically coupled to control terminals of a first transistor, a second transistor, a third transistor and a fourth transistor in a power factor correction module, wherein the first transistor and the second transistor are configured to achieve power factor correction, and the third transistor and the fourth transistor are configured to achieve synchronous rectification, and wherein the controller is configured to:
in a first time period defined by a first voltage threshold and a second voltage threshold on an AC voltage applied to the power factor correction module, control the third transistor and the fourth transistor to be off;
in the first time period and before a zero-crossing of the AC voltage, control the first transistor and the second transistor to be off;
in the first time period and after the zero-crossing of the AC voltage, control at least one of the first transistor and the second transistor to switch at a targeted switching frequency with a gradually increased duty cycle; and
after the first time period, control the first transistor and the second transistor to switch at a switching frequency lower than the targeted switching frequency.