Application NoteControl Driven SynchronousRectifiers In Phase Shifted FullBridge ConvertersApplication NoteSLUA287 – March 20032Control Driven Synchronous Rectifiers In Phase Shifted Full Bridge ConvertersControl Driven Synchronous Rectifiers In Phase ShiftedFull Bridge ConvertersSteve MappusPower Supply Control ProductsABSTRACTDriving a current doubler synchronous rectification output stage can be a very complex task,especially for a phase shifted full bridge topology. However, using the A and B outputs of theUCC3895 along with the UCC37324 dual 4-A MOSFET driver, direct PWM control of asynchronous rectifier current doubler output stage achieves. This technique provides theproper gating and timing signals necessary to accurately synchronize output switching toprimary side bridge switching.CONTENTS1Introduction3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Synchronous Rectifier Switching Requirements5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3An Easier Method6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Application Diagram8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Conclusion9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4References9....
