Active load circuit

摘要

An active load circuit applicable to a power supply. The active load circuit includes a control circuit, a dummy load and an active switching circuit. The control circuit is coupled to a ground terminal, an output terminal of a power supply and the detection circuit. The dummy load is coupled to the output terminal The active switching circuit is coupled to the control circuit, the dummy load and the ground terminal. The control circuit receives an output voltage via the output terminal and receives a power-good input signal via the detection circuit. When a voltage level of the power-good input signal is lower than a threshold value, the control circuit controls the active switching circuit to enter a load-on mode so that the dummy load is connected to the ground terminal and that the output terminal is connected to the dummy load.

主权项

1. An active load circuit applicable to a power supply, said power supply comprising a transformer, an output terminal and a detection circuit, said detection circuit being coupled to a secondary side of said transformer to detect a voltage on said secondary side and correspondingly generate a power-good input signal, said active load circuit comprising:
a control circuit, coupled to said output terminal, said detection circuit and a ground terminal, said control circuit receiving an output voltage and said power-good input signal via said output terminal and said detection circuit; a dummy load, coupled to said output terminal; and an active switching circuit, coupled to said control circuit, said dummy load and said ground terminal; wherein, when a voltage level of said power-good input signal is lower than a threshold value, said control circuit controls said active switching circuit to enter a load-on mode so that said dummy load is connected to said ground terminal and that said output terminal is connected to said dummy load.