LOW POWER CONNECTION DETECT METHOD AND SYSTEM FOR USB CHARGING

摘要

A USB hub has a USB hub controller, and an embedded controller, a USB port connector and associated port power control device and a controllable bypass switch providing a supply voltage to the USB port connector when the embedded controller enables it, a controllable voltage supply regulator unit providing a first output voltage which can be turned off and supplied to the port power control device, and a programmable current monitor circuit with a current sensor providing a second supply voltage to the monitor circuit, wherein during a low power mode, the USB hub controller and any port power control device are turned off and the monitor circuit is configured to provide the second supply voltage through the sensor and bypass switch to the USB connector and detects a current when a USB device is plugged into the USB port connector and wakes up the embedded controller.

主权项

1. A universal serial bus (USB) hub, comprising:
a USB hub controller; an embedded controller configured to operate in a normal operating mode and a low power mode and coupled with the USB hub controller, wherein the embedded controller is configured to turn the USB hub controller on or off; at least one USB port connector and associated port power control device coupled with the USB hub controller and an associated controllable bypass switch coupled with the embedded controller which is configured to provide a supply voltage to the at least one USB port connector when the embedded controller enables said associated controllable bypass switch; a controllable voltage supply regulator unit having at least one output providing a first output voltage, wherein the at least one output can be controlled by the embedded controller to be turned off, wherein the at least one output of the regulator is coupled with the port power control device of said at least one USB port connector; and a programmable current monitor circuit comprising a current sensor coupled with the at least one output of the regulator unit, wherein the regulator unit comprises an internal second supply voltage regulator providing a second supply voltage to the programmable current monitor circuit, wherein during a low power mode, the USB hub controller and any port power control device are turned off and the programmable current monitor circuit is further configured to provide the second supply voltage through the current sensor and bypass switch to said at least one USB port connector and wherein the programmable current monitor circuit detects a current flowing from the internal second supply voltage regulator through the at least one USB port connector when a USB device is plugged into the at least one USB port connector and is configured to wake up the embedded controller.