Patent ID: 7885084

Claim:
A control circuit for soft switching and synchronous rectifying of a power converter, comprising: an integrated synchronous rectifier comprising: a cathode terminal, coupled to a secondary side of a power transformer; an anode terminal, coupled to an output of the power converter; a first input-signal terminal; and a second input-signal terminal, wherein the integrated synchronous rectifier includes a controller and a power transistor connected between the cathode terminal and the anode terminal; and the first input-signal terminal and the second input-signal terminal are coupled to the controller to receive a pulse signal for switching on/off the power transistor; a switching-signal circuit comprising: an input terminal coupled to receive a switching signal; a first output-signal terminal; and a second output-signal terminal, wherein the switching signal is used for regulating the power converter by switching the power transformer; the first output-signal terminal and the second output-signal terminal are coupled to a pulse generation circuit to generate the pulse signal in response to a leading edge and a trailing edge of the switching signal; and an isolation device, coupled between the first input-signal terminal and the second input-signal terminal of the integrated synchronous rectifier, and the first output-signal terminal and the second output-signal terminal of the switching-signal circuit.