US 12,308,747 B2
Control method and power controller for flyback power converter
Hsin Hung Lu, Zhubei (TW); San-Yi Li, Zhubei (TW); and Hung-Ting Hsu, Zhubei (TW)
Assigned to LEADTREND TECHNOLOGY CORPORATION, Zhubei (TW)
Filed by Leadtrend Technology Corporation, Zhubei (TW)
Filed on Dec. 19, 2022, as Appl. No. 18/067,846.
Claims priority of application No. 111115296 (TW), filed on Apr. 21, 2022.
Prior Publication US 2023/0344356 A1, Oct. 26, 2023
Int. Cl. H02M 3/335 (2006.01); H02M 1/08 (2006.01); H02M 1/00 (2006.01)
CPC H02M 3/33523 (2013.01) [H02M 1/08 (2013.01); H02M 1/0025 (2021.05)] 13 Claims
OG exemplary drawing
 
1. A control method in use of a power converter with a primary side and a secondary side galvanically isolated from each other, the control method comprising:
receiving a feedback voltage in the primary side;
turning OFF a main power switch to start an OFF time; and
during a first period within the OFF time, constraining the feedback voltage in response to a voltage sample;
in a sampling time within the OFF time, sampling the feedback voltage to update the voltage sample, wherein the voltage sample represents an output voltage in the secondary side; and
providing a driving signal in response to the voltage sample to control the main power switch;
wherein the first period is ahead of the sampling time.