| 主权项 |
1. A power supply circuit comprising:
a basic input output system(BIOS), configured to output a first control signal and a second control signal; a signal input control circuit configured to receive the first control signal and the second control signal output from the BIOS, and to output a first selection signal according to a respective states of the first control signal and the second control signal; a power output control circuit comprising:
a first output control circuit configured to receive the first control signal and to output a first voltage;a second output control circuit configured to receive the second control signal and to output a second voltage;a third output control circuit configured to receive the first control signal and the second control signal, and further configured to output a second selection signal output a third voltage and a second selection signal; and a power output switching circuit configured to receive the first selection signal and the second selection signal and to output a first switching signal and a second switching signal to the first and second output control circuits according to respective states of the first selection signal and the second selection signal; wherein when the first and the second control signals are both in a first signal state, the power supply circuit controls an external device to communicate with a computer host; wherein when the first control signal is in a second signal state, and the second control signal is in the first signal state, the first output control circuit outputs the first voltage; wherein when the first control signal is in the first signal state, the second control signal is in the second signal state, the second output control circuit outputs the second voltage; and wherein when the first and the second control signals are both in the second signal state, the third output control circuit outputs the third voltage. |
