Converter with synchronous rectifier with ZVS

摘要

A control method for a first synchronous rectifier and a second synchronous rectifier in a switching power converter is presented. The switching power converter includes a transformer, and a first switching device and a second switching device connected in series and in parallel with an input voltage source. The first synchronous rectifier is connected with a low end of a secondary winding of the transformer. The second synchronous rectifier is connected with a high end of the secondary winding of said transformer. The first switching device is connected with a high end of the input voltage source, and the second switching device is connected with a low end of the input voltage source. The control includes the steps of driving the first switching device to an on state and the second switching device to an off state; and driving the second synchronous rectifier to an off state after the second switching device has been driven to an on state, such that a power is delivered from the primary winding to the secondary winding.