A resonant or semi-resonant DC/DC converter makes use of one or more synchronous rectification (SR) switches for rectifying an output current that is provided to a load of the converter. The SR switches are ideally turned off when zero current is flowing through them. To achieve such zero-current switching, the current through each of the SR switches is monitored and compared against a turn-off threshold. The turn-off threshold for a particular SR switch is determined from the slope of a waveform of the current together with a transition delay for turning off the SR switch. This transition delay typically includes a delay through a driver circuit for the SR switch together with a latency through the SR switch itself. Once it is detected that the current for an SR switch has dropped to or below the turn-off threshold, a signal is provided to the SR switch turning it off.