Power control circuit for universal serial bus

摘要

A power control circuit of a universal serial bus (USB) includes a USB interface, a north bridge chipset and a current control circuit. The USB interface has a power pin and a plurality of data pins. The north bridge chipset has a state pin and a plurality of signal pins connected to the data pins of the USB interface respectively. The current control circuit is connected between the power pin of the USB interface and the state pin of the north bridge chipset, the north bridge chipset controls the state of the current control circuit and further controls the output power at the power pin of the USB interface. The power control circuit can offer different output powers in accordance with different external devices.