Patent ID: 8909951

Claim:
A dynamic power management system for universal serial bus (USB) hub, the dynamic power management system comprising: a host device; a power unit, generating a supplying current; and a USB hub device coupled to the host device and the power unit, establishing a communication link to the host device and receiving the supplying current, the USB hub device comprising: a plurality of ports having a upstream port and a plurality of downstream ports wherein the host device is coupled to the USB hub device via the upstream port; a power management module, receiving the supplying current and calculating an available current based on the supplying current; and a hub function module coupled to the power management module and the ports respectively, detecting and managing the ports; wherein the power management module compares the available current with a request current of a peripheral device when the peripheral device is connected to one of the ports and the hub function module determines an execution mode of the port connected to the peripheral device based on the compared result between the available current and the request current, and wherein the power management module acquires the request current when the USB hub device inquires the host device; and wherein if the available current is less than the request current, the execution mode of the port connected to the peripheral device is downgraded and the peripheral device is reconnected to the one of the ports, the power management module acquires the request current when the USB hub device inquires the host device again.