CONTROL CIRCUIT FOR SWITCHING POWER CONVERTERS WITH SYNCHRONOUS RECTIFIERS

摘要

A control circuit for switching power converters with synchronous rectifiers is disclosed for providing start-up and shut-down protection. The control circuit for switching power converters with synchronous rectifiers includes a means for blocking the driving signals to the synchronous rectifiers, a voltage sampling circuit, a reference voltage, and a comparator. The comparator compares a sample voltage to a reference voltage to determine when to block and when to admit driving signals to the synchronous rectifiers. The control circuit for switching power converters with synchronous rectifiers is particularly useful for minimizing component damage due to start-up and shut-down transients as compared to converters known in the art.

主权项

1. A power converter fed by a primary voltage, said power converter having synchronous rectifying elements and producing a secondary voltage, the power converter comprising:
driving circuitry for said synchronous rectifying elements; blocking circuitry connected between said driving circuitry and said synchronous rectifying elements; secondary voltage sampling circuitry; and control circuitry which activates said blocking circuitry in the event that said secondary voltage sampling circuitry indicates a secondary voltage below a preconfigured value.