Patent attributes
A power management circuit adapted for a portable electronic device is provided. The portable electronic device receives a supply voltage from a USB power supplying port through a built-in USB charging port. The power management circuit includes a USB detection unit, a voltage detection unit, and a control unit. The USB detection unit determines the type of the USB power supplying port. The voltage detection unit detects the supply voltage. The control unit configures the power consumption of the portable electronic device based on the type of the USB power supplying port and the supply voltage. When the portable electronic device initiates booting process with the USB power supplying port being the Dedication Charging Port and the supply voltage being lowered than a threshold, the control unit reduces the power consumption of the portable electronic device to maintain the supply voltage above the threshold for booting stably.
