Patent ID: 9729043
Date: 2017-08-08
CPC Classifications: H02M

Claim:
1. A power conversion apparatus comprising: a power conversion circuit configured to convert an input voltage to an output voltage, the power conversion circuit having a power switch, a control terminal of the power switch receiving a pulse width modulation signal, a conduction state of the power switch being switched according to the pulse width modulation signal, so as to convert the input voltage to the output voltage; a current sensing unit coupled to the power switch, the current sensing unit sensing a current flowing through the power switch and outputting a current sensing signal; and a control chip coupled to the power conversion circuit and the current sensing unit, the control chip outputting the pulse width modulation signal according to the current sensing signal, wherein when a duty cycle of the pulse width modulation signal is greater than or equal to a preset duty cycle for two or more consecutive signal cycles and a voltage of the current sensing signal is smaller than a preset voltage during the two or more consecutive signal cycles, the control chip stops switching the power switch, such that the power conversion apparatus enters a protection mode.