Controller and control method of power converter

Abstract

A controller for a power converter includes a current sensing circuit, an overcurrent protection circuit, a compensation circuit, and a pulse width modulation (PWM) signal generation circuit. The overcurrent protection circuit receives a current sensing signal from the current sensing circuit sensing the output current and generates an overcurrent protection signal in response to the output current exceeding a preset value. The compensation circuit receives a reference voltage, an output voltage, and the overcurrent protection signal to generate a compensation signal. The PWM signal generation circuit receives the overcurrent protection signal and the compensation signal to generate a control signal. The compensation circuit includes a voltage adjustment circuit and an error amplifier circuit. The voltage adjustment circuit receives the reference voltage, the output voltage, and the overcurrent protection signal, and is controlled by the overcurrent protection signal to generate an adjusted reference voltage. The error amplifier circuit receives the adjusted reference voltage and the output voltage to generate a compensation signal, which is then sent to the PWM signal generation circuit.

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