MOS transistor control circuit for synchronous rectifier

摘要

The circuit has a delay unit to delay closing of a MOS transistor (1) with respect to zero crossing of a sinusoidal voltage (Vd) at cathode (K) and anode (A) terminals of the transistor. A triggering unit triggers the transistor to its on state. A capacitor (5) and a diode (4) are connected in series between the terminals to provide a supply voltage to the circuit. The capacitor is charged when the transistor is in on state.