A method involves receiving, at an active clamp controller circuit, an active clamp switch current that passes through an active clamp switch. The active clamp switch is enabled using the active clamp controller circuit in response to determining, based on the active clamp switch current, body-diode conduction of the active clamp switch. The active clamp switch is disabled using the active clamp controller circuit in response to determining, based on the active clamp switch current, a first zero-crossing of the active clamp switch current and a second zero-crossing of the active clamp switch current.