US 11,843,320 B2
Method of operating isolated resonant converter with synchronous rectifier
Ramkumar Sivakumar, Bangalore (IN); Brent Alan McDonald, Murphy, TX (US); and Yalong Li, Allen, TX (US)
Assigned to TEXAS INSTRUMENTS INCORPORATED, Dallas, TX (US)
Filed by Texas Instruments Incorporated, Dallas, TX (US)
Filed on Jun. 29, 2021, as Appl. No. 17/362,875.
Prior Publication US 2022/0416676 A1, Dec. 29, 2022
Int. Cl. H02M 3/335 (2006.01); H02M 1/00 (2006.01)
CPC H02M 3/33592 (2013.01) [H02M 1/0035 (2021.05)] 15 Claims
OG exemplary drawing
 
1. A method for operating a resonant converter in a burst mode, the method comprising:
determining a polarity of a transformer voltage across a secondary winding of a transformer;
determining, from the polarity of the transformer voltage, an on/off state of first and second transistors coupled to the secondary winding of the transformer; and
commencing a burst period by alternately turning on/off a high-side transistor and a low-side transistor in response to the transformer voltage having a first polarity, wherein the high-side transistor and the low-side transistor are being coupled to a primary winding of the transformer; and
holding the resonant converter in a burst interval by delaying a start of a first pulse of the burst period in response to the transformer voltage having a second polarity, wherein the high-side transistor and the low-side transistor are turned off during the burst period.