A DC to DC power converter includes synchronous rectifiers which respond
to a control waveform. Negative current from a load into the power
converter is prevented by increasing the converter output voltage at a
minimum current limit. The synchronous rectifiers may be held off in
response to decision logic by activation of a hold-off circuit connected
to a control terminal of a synchronous rectifier or of an ORing
transistor at the converter output. When the synchronous rectifier is
subsequently enabled, its control waveform may be increased slowly
relative to the switching cycle.