RECTIFIER CIRCUIT AND POWER SUPPLY USING SAME

Provided is a rectifier circuit for implementing synchronous rectification using a rectification MOSFET, wherein the capacity and the volume of a capacitor for supplying power for controlling the rectification MOSFET can be reduced while maintaining a loss reduction effect produced by the synchronous rectification. The present invention is characterized in that: a first MOSFET, a second MOSFET, a first control circuit, and a second control circuit are provided; the second MOSFET is in a non-rectification period when the first MOSFET is in a rectification period; the first MOSFET is in a non-rectification period when the second MOSFET is in a rectification period; the first control circuit outputs a voltage generated on the basis of a first input voltage as a first output voltage between the gate and the source of the first MOSFET in at least a portion of a period in which a voltage between the drain and the source of the second MOSFET is inputted as the first input voltage and a negative voltage is applied between the drain and the source of the first MOSFET; the second control circuit outputs a voltage generated on the basis of a second input voltage as a second output voltage between the gate and the source of the second MOSFET in at least a portion of a period in which a voltage between the drain and the source of the first MOSFET is inputted as the second input voltage and a negative voltage is applied between the drain and the source of the second MOSFET; when the first input voltage is equal to or greater than a prescribed first threshold voltage, the first control circuit clamps the first output voltage to the first threshold voltage; and, when the second input voltage is equal to or greater than a prescribed second threshold voltage, the second control circuit clamps the second output voltage to the second threshold voltage.