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 includes a mirror current source, an integrating capacitor, a compensation unit, a switch circuit and a signal processing unit; the mirror current source includes a first current source and a second current source; the compensation unit is used to compensate the inherent capacitance of the measured capacitor to reduce the The magnitude of the current flowing through the integral capacitor caused by the inherent capacitance of the small measured capacitor; the switch circuit is used for selective conduction, so that the charge initialization is performed on the integral capacitor during the initialization phase, and the measured capacitor is charged during the charging and discharging phase. Discharging, after discharging the measured capacitor, the first current source charges the measured capacitor through the switch circuit, and the second current source charges the integrating capacitor through the switching circuit; the signal processing unit is connected with the integrating capacitor for satisfying Determine the capacitance value of the measured capacitor under preset conditions. The capacitance detection circuit disclosed in the present application 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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