US 12,218,602 B2
Switch mode power converter with synchronous rectifier implementing adaptive gate voltage regulation for fast turn-off
Sitthipong Angkititrakul, Dublin, CA (US); Yu Ding, Shanghai (CN); and Jian Yin, San Ramon, CA (US)
Assigned to Alpha and Omega Semiconductor International LP, Toronto (CA)
Filed by Alpha and Omega Semiconductor International LP, Toronto (CA)
Filed on Nov. 22, 2022, as Appl. No. 18/058,219.
Prior Publication US 2024/0171083 A1, May 23, 2024
Int. Cl. H02M 3/335 (2006.01); H02M 1/36 (2007.01)
CPC H02M 3/33592 (2013.01) [H02M 1/36 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of operating a power converter incorporating a synchronous rectifier and receiving an input voltage and providing an output voltage, the method comprising:
detecting a start of a synchronous rectifier (SR) conduction cycle;
detecting a voltage indicative of a drain current of the synchronous rectifier;
in response to the detected voltage indicating the drain current has a first slope value, selecting a first gate discharge current;
in response to the detected voltage indicating the drain current has a second slope value less than the first slope value, selecting a second gate discharge current less than the first gate discharge current; and
discharging a gate voltage of the synchronous rectifier using the selected gate discharge current in response to a drain voltage at a drain terminal of the synchronous rectifier reaching a first regulation threshold.