US 11,799,381 B2
Controller for a flyback converter
Jose Vidal, Phoenix, AZ (US); and Dinesh Katam, Tempe, AZ (US)
Assigned to TEXAS INSTRUMENTS INCORPORATED, Dallas, TX (US)
Filed by Texas Instruments Incorporated, Dallas, TX (US)
Filed on Nov. 30, 2021, as Appl. No. 17/537,855.
Prior Publication US 2023/0170808 A1, Jun. 1, 2023
Int. Cl. H02M 3/335 (2006.01); H02M 1/08 (2006.01)
CPC H02M 3/33569 (2013.01) [H02M 1/083 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A control circuit for a converter, comprising:
a valley sensing circuit coupled to a switch terminal, wherein the valley sensing circuit is configured to detect valleys in an oscillating voltage at the switch terminal, the valley sensing circuit having a valley sense output and is configured to provide a first control signal at the valley sense output responsive to an occurrence of a valley;
a logic gate having a logic output, wherein the logic gate is configured to assert a second control signal at the logic output to turn on a switching transistor coupled to the switch terminal; and
a switch-on control circuit having first and second switch-on inputs, wherein the first switch-on input is coupled to the valley sense output, the second switch-on input is coupled to the logic output, and the switch-on control circuit is configured to assert a third control signal to turn on the switching transistor responsive to the second control signal indicating that the switching transistor is to be turned on while the first control signal indicates occurrence of a valley.