| 主权项 |
1. A power conversion apparatus, comprising:
a transformer, having a primary side and a secondary side, wherein a first end of the primary side is configured to receive an input voltage, and the secondary side is configured to provide an output voltage to an electronic apparatus; a power switch, having a first terminal coupled to a second end of the primary side, a second terminal coupled to a first node, and a control terminal receiving a pulse width modulation (PWM) signal; a first resistor, coupled between the first node and a ground voltage; a first comparison unit, comparing a voltage of a feedback signal related to a load status of the electronic apparatus with a first reference voltage to generate a first comparison signal; a counting unit, coupled to the first comparison unit to receive the first comparison signal, wherein when the voltage of the feedback signal is greater than the first reference voltage, the first comparison unit enables the counting unit; a second comparison unit, coupled to the first node and the counting unit, and comparing a voltage of the first node with a second reference voltage to generate a second comparison signal, wherein the counting unit counts a number of times the voltage of the first node exceeding the second reference voltage according to the second comparison signal; and a PWM control unit, coupled to the counting unit and the control terminal of the power switch, and stopping generating the PWM signal used for switching the power switch when a counting value of the counting unit is greater than a predetermined value. |
