A USB charging device access detection system and method

Abstract

The invention discloses a USB charging equipment access detection system and method. The method comprises the following steps: step 1, starting detection, and enabling a USB port to be suspended; step2, pulling up the voltage of a USB pin to be higher than a first reference voltage V1; step 3, continuously comparing the voltage of the USB pin with a second reference voltage V2 until the voltage of the USB pin is detected to be lower than the second reference voltage V2; step 4, stopping pulling up the USB pin voltage, comparing the USB pin voltage with a third reference voltage V3 within settime, determining charging equipment access under the condition that the USB pin voltage is lower than the third reference voltage V3, and starting a charging action; and under the condition that thevoltage of the USB pin is higher than the third reference voltage V3, determining that the USB pin is in contact with the human body and returning to the step 2. According to the invention, whether the access is access detection false triggering caused by human body contact or charging equipment acess can be judged.

Description

technical field [0001] The invention relates to the technical field of USB charging, in particular to a USB charging device access detection system and method. Background technique [0002] Currently on the market, devices for charging portable electronic products (hereinafter referred to as power supply devices) are mainly divided into two categories: chargers that require an external power source and mobile power sources with their own batteries. For chargers, the user's usage habits are generally to directly unplug the charged electronic products, and leave the charger on the power socket or vehicle power supply. At this time, the adapter often needs to enter the standby state to reduce power consumption. When the charger enters the standby state, how to identify the access of the charging device is a problem, which requires the use of the charging device access detection technology to detect the access of the charging device. [0003] If the charger is a multi-output ch...

AI Technical Summary

Problems solved by technology

However, due to the low impedance of the human body, it is easy to form a low-impedance path between the USB pin and GND when it is touched, which will lower the voltage of the USB pin, causing the power supply device to mistakenly believe that there is a charging device connected and carry out subsequent corresponding actions. operate

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