US 11,909,325 B2
Circuit for generating a dynamic drain-source voltage threshold and method thereof
Yuedong Chen, Chengdu (CN)
Assigned to Chengdu Monolithic Power Systems Co., Ltd., Chengdu (CN)
Filed by Chengdu Monolithic Power Systems Co., Ltd., Chengdu (CN)
Filed on Nov. 8, 2021, as Appl. No. 17/521,000.
Claims priority of application No. 202011286140.1 (CN), filed on Nov. 17, 2020.
Prior Publication US 2022/0158565 A1, May 19, 2022
Int. Cl. H02M 3/335 (2006.01); H02M 1/08 (2006.01); H02M 1/00 (2006.01)
CPC H02M 3/33592 (2013.01) [H02M 1/08 (2013.01); H02M 1/0025 (2021.05)] 19 Claims
OG exemplary drawing
 
1. A drain-source threshold setting circuit to control a synchronous rectifier, comprising:
a capacitor;
an amplifier, configured to receive a drain-source voltage across the synchronous rectifier and a capacitor voltage across the capacitor, and to provide a first current to charge the capacitor based on an amplified error between the drain-source voltage and the capacitor voltage;
a buffer circuit, configured to receive the capacitor voltage, and to provide a dynamic drain-source voltage threshold based on the capacitor voltage; and
a discharging circuit, configured to receive the drain-source voltage and the dynamic drain-source voltage threshold, and to discharge the capacitor based on a comparison result of the drain-source voltage and the dynamic drain-source voltage threshold.