USB (universal serial bus) interface charge handshaking method and quickly-chargeable power adapter

Abstract

The invention provides a USB (universal serial bus) interface charge handshaking method and a quickly-chargeable power adapter. The method includes that the power adapter and USB equipment are connected through a USB cable; a charge management circuit of the USB equipment controls connection and disconnection of a VBUS according to agreed codes precured by the USB equipment; the power adapter restores the agreed codes precured on the USB equipment by identifying connection and disconnection of the VBUS; if the restored agreed codes on the USB equipment are consistent with agreed codes precured by the power adapter, showing that handshaking succeeds, and otherwise, showing that handshaking fails. The power adapter comprises a VBUS current detection circuit, a control circuit A and an AC / DC (alternating current / direct current) circuit, wherein the control circuit A and the AC / DC circuit are connected to the output end of the VBUS current detection circuit sequentially. On the premise that output current of the power adapter is unchanged, output voltage provided by the power adapter to the USB equipment is increased, higher input power is provided, and charging is accelerated.

Description

technical field [0001] The invention belongs to the field of USB interface charging, and in particular relates to a USB interface charging handshake method and a fast-charging power adapter. Background technique [0002] There are currently two charging voltages based on the USB interface. Option one is the standard 5.0V voltage output, and the voltage is not variable. The second scheme is represented by Qualcomm in the United States. The output voltage is variable. The USB device and the power adapter shake hands through the DP and DM signals of the USB interface to determine whether the output voltage is 5.0V output or other high-voltage output, which has reached high voltage. The purpose of power transmission and fast charging. [0003] The disadvantage of the first solution above is that it cannot output high voltage to provide large input power to the charging chip; the disadvantage of the second solution is that the USB device and the power adapter need to identify D...

AI Technical Summary

Problems solved by technology

[0003] The disadvantage of the first solution above is that it cannot output high voltage to provide large input power to the charging chip; the disadvantage of the second solution is that the USB device and the power adapter need to identify DP and DM signals of different logics, which requires high hardware circuits and high implementation costs.

[0004] At present, there is no unified USB fast charging standard in the communication industry. The fast charging method represented by Qualcomm has the defect of the second solution. It is very meaningful to develop a simple and reliable USB interface handshake method for hardware implementation to meet the needs of fast charging.

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