Power conversion device with synchronous rectifier driving and voltage oscillation limitation during a discontinuous operating mode

摘要

A power conversion device includes a first and second input terminal for connection to a transformer winding and at least an output terminal. A first and second synchronous rectifier are associated with the first and second input terminals, respectively. An inductor within an output stage is connected between the first input terminal and the output terminal. A driving circuit includes first and second output terminals connected to respective control terminals of the first and second synchronous rectifiers. An adjustable threshold control block is connected between the first and second input terminals and is connected to the inductor. The control block is enabled responsive to a control signal on the first output terminal of the driving circuit. The control block operates to clamp the voltage of the first input terminal to a preset value during at least a dead time period of the device operation.