Synchronous rectifier control circuits of power converters

摘要

A synchronous rectifying control circuit of a power converter is provided. The synchronous rectifying control circuit comprises a synchronous rectifying driver, a charge pump capacitor, and a capacitor. The synchronous rectifying driver is coupled to a transformer for generating a control signal to switch a transistor. The charge pump capacitor is coupled to a power source for generating a charge pump voltage. The capacitor is coupled to store the charge pump voltage. The transistor is coupled to the transformer and operated as a synchronous rectifier. The charge pump voltage is coupled to guarantee a sufficient driving capability for the control signal.

主权项

1. A synchronous rectifying control circuit with charge pump of a power converter, comprising:
a synchronous rectifying driver, coupled to a transformer for generating a control signal to switch a transistor; a charge pump capacitor, coupled to a power source; a plurality of switches, when a voltage level of said power source is lower than a threshold, coupled to charge said charge pump capacitor by said power source in a switching manner to generate a charge pump voltage for charge pump; and a capacitor, coupled to store said charge pump voltage; wherein said transistor is coupled to said transformer and operated as a synchronous rectifier; and wherein said charge pump voltage is coupled to guarantee a sufficient driving capability for said control signal.