Patent ID: 8627122

Claim:
A Universal Serial Bus (USB) charging circuit for a computer, comprising: a USB interface; a USB power terminal connected with the USB interface to supply power to the USB interface when the computer is in an ON state or a sleep state; a standby power terminal connected with the USB interface to supply power to the USB interface when the computer is in a hibernation state or in an OFF state; a switch unit for generating a first switch signal to connect the standby power terminal to the USB interface, and generating a second switch signal to disconnect the standby power terminal from the USB interface; an Integrated Circuit (IC) chip for outputting a first control signal when the computer is in the sleep state, and outputting a second control signal when the computer is in the hibernation state or in the OFF state; and a control unit connected with the USB power terminal, the standby power terminal, the switch unit, the USB interface, and the IC chip, wherein the control unit disconnects the USB interface from the standby power terminal when receiving a high voltage level from a system power terminal or the first control signal from the IC chip; the control unit connects the standby power terminal to the USB interface when receiving the second control signal from the IC chip and the first switch signal from the switch unit; the control unit disconnects the standby power terminal supply from the USB interface when receiving the second control signal from the IC chip and the second switch signal from the switch unit.