Control circuits and control methods for over voltage protection in power suppliers

摘要

Disclosed include a control circuit adapted for a power controller powered by an operation voltage. When the operation voltage exceeds an over-voltage reference, the power controller stops power conversion provided by a power converter. The control circuit comprises a slope detector detecting a variation slope of the operation voltage. When the variation slope exceeds a drop rate, the slope detector recovers the power conversion. When the power conversion is recovered the power controller compares the operation voltage with the over-voltage reference.

主权项

1. A control method for over-voltage protection adapted for a power controller controlling a power converter regulating an output voltage to supply power to a load, comprising:
detecting an operation voltage, wherein the operation voltage powers the power controller; detecting a variation slope of the operation voltage; comparing the operation voltage with an over-voltage reference; comparing the variation slope of the operation voltage with a drop rate; stopping power conversion provided by the power converter when the operation voltage exceeds the over-voltage reference; and recovering the power conversion when the variation slope exceeds the drop rate.