Capacitance detection circuit and its control method

Abstract

The invention relates to the field of electronic technology, and discloses a capacitance detection circuit and a control method thereof. In the present invention, the capacitance detection circuit includes: a switched capacitor amplifier, a comparator, and a timing control unit; the switched capacitor amplifier includes a variable capacitor array with N capacitor branches connected to the capacitor to be detected; wherein, N is a natural number and N> 1; the first input terminal of the comparator is connected to the output terminal of the switched capacitor amplifier, and the second input terminal of the comparator is connected to the first reference voltage; the input terminal of the timing control unit is connected to the output terminal of the comparator, and the timing control unit’s The output end is connected to the capacitance adjustment end of the variable capacitance array. The embodiment of the present invention also provides a control method of the capacitance detection circuit. The capacitance detection circuit provided by the embodiment of the present invention simplifies the circuit structure, and directly converts the capacitance value into a digital quantity, which greatly reduces the area and power consumption of the capacitance detection circuit.

Description

technical field [0001] The embodiments of the present invention relate to the field of electronic technology, and in particular to a capacitance detection circuit and a control method thereof. Background technique [0002] Currently, capacitive sensors are generally used as input devices and are widely used in various electronic systems to provide information about the input (such as position, motion, force, and duration, etc.) for the electronic system. Generally, the user operates (such as approaching, touching, pressing, sliding, etc.) one or more sensing areas of the capacitive sensor to generate a capacitive effect with the sensing area. By quantifying the capacitive effect, the user's operation can be judged . Among them, the capacitance detection circuit is the core of the capacitive sensor, and its circuit design directly affects the overall cost and power consumption of the capacitive sensor. [0003] Such as figure 1 Shown is the existing capacitance detection c...

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Problems solved by technology

[0004] However, in the process of realizing the present invention, the inventors found the following problems in the prior art: the existing capacitance detection circuit is relatively complicated, and the analog-to-digital converter ADC is used, resulting in a very large area and power consumption of the capacitance detection circuit , which is very unfavorable for capacitive sensors

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