Patent ID: 7184280

Claim:
An LLC series resonant converter, comprising: a bridge circuit, coupled to an input voltage, comprising at least one pair of power switches; a resonant network, coupled to the bridge circuit and being driven by the at least one pair of power switches; a transformer, coupled to the resonant network; a rectification circuit, coupled to the transformer, the transformer providing an output current of the LLC series resonant converter, wherein the rectification circuit comprises at least one pair of synchronous rectification power switches, one of the at last one pair of synchronous rectification power switches and one of the at least one pair of the power switches are correspondingly and electrically coupled, corresponding one of the at least one pair of synchronous rectification power switches and corresponding one of the at least one pair of power switches are synchronously on or off; and a frequency adjustment controller, coupled between the at least one pair of power switches and the at least one pair of synchronous rectification power switches, providing driving signals to the at least one pair of synchronous rectification power switches in response to an operating frequency of the LLC series resonant converter and a series resonant frequency of the resonant network, to perform synchronous rectification in the LLC series resonant converter.