Proximity detection circuit, wearable device and proximity detection method

Abstract

The present application provides a proximity detection circuit, which can improve the detection performance of the proximity detection circuit in a wearable device. The proximity detection circuit is set in the wearable device and connected to multiple detection channels. The proximity detection circuit includes: a self-capacitance drive circuit, which is used to input a self-capacity drive signal to the first detection channel, and the first detection channel is connected to an ESD protection circuit. circuit, the self-capacitance detection signal output by the first detection channel under the action of the self-capacitance drive signal is related to the self-capacitance change and the capacitance change caused by the ESD protection circuit being illuminated; the mutual-capacity drive circuit is used for the first detection One of the detection channels in the channel and the second detection channel outputs a mutual capacitance driving signal, and under the action of the mutual capacitance driving signal, the mutual capacitance detection signal output by the other detection channel is related to the mutual capacitance variation; and the signal processing circuit uses It is used to determine whether the user is close to the wearable device according to the detection result of the self-capacitance detection signal and the mutual capacitance detection signal.

Description

technical field [0001] The embodiments of the present application relate to the field of capacitance detection, and more specifically, relate to a proximity detection circuit, a wearable device, and a proximity detection method. Background technique [0002] In wearable devices, such as True Wireless Stereo (TWS) earphones, a proximity detection circuit is usually used to detect a user's touch or approach to the earphone. The proximity detection circuit can detect the change of the self-capacitance of the detection electrode in the earphone to the ground to obtain the information that the user is approaching the earphone, so as to determine the wearing condition of the earphone and make the earphone perform corresponding operations, for example, when the earphone is detected to be close to the user's ear When the playback operation is performed, the playback operation is performed when the headset is detected to be away from the user's ear, and so on. Meanwhile, in order to...

AI Technical Summary

Problems solved by technology

The TVS diode is easily affected by the external light, so that its capacitance to the ground changes. This capacitance change will affect the detection result of the self-capacitance of the detection electrode, thereby affecting the detection performance of the proximity detection circuit.

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