Detection circuit, chip and related electronic device

Abstract

The application discloses a detection circuit, a chip and related electronic devices. The detection circuit includes first and second input terminals, an input terminal of a differential integration circuit, an energy storage element, first to sixth switching circuits, and a differential integration circuit. . The detection circuit generates a detection voltage signal according to the sensing capacitance between the first input terminal and the second input terminal. The first switching circuit is coupled to the first input end, the input end of the differential integration circuit and the ground end. The second switch circuit is coupled to the second input terminal, the input terminal of the differential integration circuit and the ground terminal. The third switch circuit is coupled to the input terminal of the differential integration circuit and the operating voltage. The fourth switching circuit is coupled to the energy storage element and the ground terminal. The fifth switching circuit is coupled to the energy storage element, the ground terminal and the operating voltage. The sixth switching circuit is coupled to the first end of the energy storage element and the input end of the differential integration circuit. The differential integration circuit is used for integrating the voltage at the input end of the differential integration circuit to generate a detection voltage signal.

Description

technical field [0001] The present application relates to a detection circuit, in particular to a self-capacitance detection circuit, a chip and related electronic devices. Background technique [0002] Electronic products often involve various human-computer interactions based on capacitance detection. For example, in earphones, capacitive in-ear detection is often used to realize the wear / off detection of the earphones to control whether the earphones perform music playback and other operations, and use capacitive touch detection to realize gestures such as click, double-click, and slide Recognition, and then complete human-computer interaction in various application scenarios; for example, touch detection or gesture recognition based on capacitive detection is also involved in mobile phones and vehicle touch controls. However, as the temperature changes, the capacitance value of the detected capacitor will also change, and this phenomenon of capacitance change due to tem...

AI Technical Summary

Problems solved by technology

This change is easily misjudged as earphone wearing, falling off, or finger touch, which leads to misoperation

[0003] In addition, in the prior art, since the capacitance detection value read by the reading circuit actually includes the capacitance value change caused by the temperature, in order to reserve the capacitance value change range caused by the temperature, the reading circuit reads The effective sensing range of the detected value is quite limited, which often leads to inaccurate judgments when judging whether there is a human body approaching based on the capacitance detection value or inaccurate judgments for other applications based on the capacitance detection value

For example, the small signal amount of the effective sensing signal makes it difficult for the back-end circuit to accurately identify the effective sensing signal

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