Disclosed examples include synchronous rectifiers and flyback converters, integrated circuits and operating methods, in which a first switch is turned on to allow current to flow for a first time period in a first direction in a transformer primary winding responsive to a first switch voltage transitioning below a first threshold, and a second switch is turned on for a second time period after the first time period to transfer energy from a secondary transformer winding to drive a load. In the same converter cycle, the second switch is again turned on for a third time period in response to a second switch voltage transitioning below a second threshold at one of a series of troughs of a resonant ringing voltage waveform across the second switch, to cause current flow in a second direction in the primary winding to discharge a capacitance of the first switch to cause the first switch voltage to transition below the first threshold to initiate a subsequent converter cycle.