Capacitance detection circuit, capacitance detection method and electronic equipment

Abstract

The application discloses a capacitance detection circuit, a capacitance detection method and electronic equipment. The capacitance detection circuit comprises a mirror image current source, an integrating capacitor, a compensation unit, a switching circuit and a signal processing unit. The mirror image current source comprises a first current source and a second current source; the compensation unit is used for compensating the natural capacitance of a measured capacitor so as to reduce the magnitude of the current flowing through the integrating capacitor caused by the natural capacitance ofthe measured capacitor. The switching circuit is used for selective conduction, so that charge initialization is carried out on the integrating capacitor at the initialization stage; the tested capacitor is discharged in the charging and discharging stage, and the tested capacitor is charged through the switching circuit by the first current source and the integrating capacitor is charged throughthe second current source after the tested capacitor is discharged; and the signal processing unit is connected with the integrating capacitor and is used for determining the capacitance value of themeasured capacitor when a preset condition is met. The capacitance detection circuit disclosed by the invention has the advantages of small area and low system complexity.

Description

technical field [0001] The invention belongs to the field of capacitance detection, and in particular relates to a capacitance detection circuit, a capacitance detection method and electronic equipment. Background technique [0002] A capacitive sensor (also known as a capacitive sensor) is a conversion device that converts the measured physical quantity into a change in capacitance. Capacitive sensors have the advantages of simple structure, stable performance, and high sensitivity, and are widely used in industrial and consumer electronics products. For example: apply capacitive sensors to pressure detection, displacement detection, acceleration detection, thickness detection and liquid level detection. [0003] The capacitance detection circuit is used to detect the capacitance value of the capacitive sensor, so as to determine the size of the measured physical quantity. [0004] Traditional capacitance detection circuits such as figure 1 As shown, switch K1 and switch...

AI Technical Summary

Problems solved by technology

For cost considerations, the integrating capacitor C mod Difficult to be integrated into the chip

In practical applications, the integrating capacitor C mod Generally, it is implemented directly on the PCB with discrete capacitors. On the one hand, it requires an additional Cmod pin in the chip package. On the other hand, it leads to complex system solutions and increased costs.

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