Capacitance detection circuit, capacitance detection method, touch detection device and terminal equipment

Abstract

The present application provides a capacitance detection circuit, a capacitance detection method, a touch detection device and a terminal device, which can overcome the influence of large self-capacitance on self-capacitance detection and improve the sensitivity of self-capacitance detection. The capacitance detection circuit is used to detect the capacitance of N capacitors to be tested, where N is greater than or equal to 2, and includes: a reference capacitor, at least N-1 capacitors for converting the capacitance signal of the capacitor to be tested into a first voltage signal and The first front-end circuit for taking the difference of the first voltage signal, at least one second front-end circuit for converting the capacitance signals of the capacitor under test and the reference capacitor into a second voltage signal and taking the difference of the second voltage signal, and processing circuit; the processing circuit determines the capacitance value of each capacitor under test in the N capacitors under test according to the first differential signal output by each first front-end circuit and the second differential signal output by each second front-end circuit.

Description

technical field

[0001] The present application relates to the technical field of capacitance detection, and in particular to a capacitance detection circuit, a capacitance detection method, a touch detection device and a terminal device. Background technique

[0002] Capacitors are widely used in many terminal electronic devices, for example, touch sensors for touch control on terminal device display screens. During the use of capacitors, it is essential to measure and analyze their capacitance value. Nowadays, self-capacitance detection has become a very important measurement and analysis method.

[0003] However, since the self-capacitance is often relatively large, the existing self-capacitance detection method has low sensitivity when the self-capacitance is large; and the cancel capacitor used to improve the sensitivity is large, so that the cancel capacitor cannot be integrated, and the cost of the cancel capacitor Furthermore, the increase of the self-capacitance red...

Images