Patent ID: 11901813
Assignee: ON-BRIGHT ELECTRONICS (SHANGHAI) CO., LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 21:
22. A method for a quasi-resonant switching power supply, the method comprising:
receiving a voltage signal;
detecting one or more voltage valleys of the voltage signal in magnitude;
generating a detection signal representing the detected one or more voltage valleys;
receiving one or more signals;
generating a mode control signal that indicates a selected valley-locking mode based at least in part on the one or more signals;
selecting from the detected one or more voltage valleys, one or more valleys that correspond to the selected valley-locking mode;
generating a valley control signal indicating the one or more selected valleys;
processing information associated with the valley control signal;
generating a drive signal based on at least information associated with the valley control signal; and
changing the drive signal from a first logic level to a second logic level to start multiple switching cycles in response to the one or more selected valleys;
wherein, in the selected valley-locking mode, the selecting from the detected one or more voltage valleys, one or more valleys that correspond to the selected valley-locking mode includes:
selecting one or more nth valleys of the voltage signal and one or more (n+1)th valleys of the voltage signal as the one or more selected valleys, n being a positive integer;

wherein, in the selected valley-locking mode, the changing the drive signal from a first logic level to a second logic level to start multiple switching cycles in response to the one or more selected valleys includes:
starting one or more first switching cycles of the multiple switching cycles at the one or more nth valleys of the voltage signal respectively; and
starting one or more second switching cycles of the multiple switching cycles at the one or more (n+1)th valleys of the voltage signal respectively.