US 11,817,791 B2
Synchronous rectifier driver circuit, related integrated circuit, electronic resonant converter and method
Alberto Iorio, Aosta (IT); Maurizio Foresta, Aosta (IT); Emilio Volpi, Charvensod (IT); and Jan Novotny, Tyn nad Vltavou (CZ)
Assigned to STMicroelectronics S.r.l., Agrate Brianza (IT); and STMicroelectronics Design and Application S.R.O., Prague (CZ)
Filed by STMicroelectronics S.r.l., Agrate Brianza (IT); and STMicroelectronics Design and Application S.R.O., Prague (CZ)
Filed on Sep. 30, 2021, as Appl. No. 17/490,793.
Claims priority of application No. 102020000023497 (IT), filed on Oct. 6, 2020.
Prior Publication US 2022/0109375 A1, Apr. 7, 2022
Int. Cl. H02M 3/335 (2006.01); H02M 1/08 (2006.01); H02M 3/00 (2006.01); H02M 1/00 (2006.01)
CPC H02M 3/33592 (2013.01) [H02M 1/0058 (2021.05); H02M 3/01 (2021.05); H02M 1/08 (2013.01)] 16 Claims
OG exemplary drawing
 
15. A method of operating a synchronous rectifier driver circuit,
wherein said synchronous rectifier driver circuit includes a first terminal configured to be connected to a source terminal of a synchronous rectifier FET; a second terminal configured to be connected to a drain terminal of said synchronous rectifier FET; a third terminal configured to be connected to a gate terminal of said synchronous rectifier FET, and
the method comprises:
measuring a voltage between said second terminal and said first terminal;
detecting a switch-on instant wherein said measured voltage reaches a first threshold value;
detecting a switch-off instant wherein said measured voltage reaches a second threshold value;
generating a drive signal between said third terminal and said first terminal as a function of said measured voltage by:
between a further instant and said switch-off instant, varying said drive signal as a function of the instantaneous value of said measured voltage; and
between said switch-off instant and the next switch-on instant, setting said drive signal to a first value;
determining said further instant by determining an instant where said measured voltage reaches a peak value between said switch-on instant and said switch-off instant;
between said switch-on instant and said further instant, setting said drive signal to a second value;
storing, by a sample-and-hold circuit of said synchronous rectifier driver circuit, said peak value; and
determining said second value as a function of said stored peak value.