Accelerometer capacitance detection circuit

Abstract

The invention discloses an accelerometer capacitance detection circuit. The accelerometer capacitance detection circuit comprises a modulator structure module, a capacitance compensation array module, a digital-to-analog conversion circuit module, and an input common mode compensation circuit module. The capacitance compensation array is connected with the front end of the first stage switch capacitance integrator of the modulator module, and the digital-to-analog conversion circuit is connected with the first stage switch capacitance integrator under control of one-bit digital output. The input common mode compensation circuit is used to sample the output of the first stage switch capacitance integrator, and is used to acquire a common mode voltage, and is used to feed the common mode voltage back to the input of the first stage switch capacitance integrator to eliminate an input common mode voltage deviation. Problems that the conventional accelerometer capacitance detection circuits are easily affected by environmental and own factors, power consumption is high, and processing is inconvenient are solved, and therefore the accelerometer capacitance detection circuit is advantageous in that circuit design is reasonable, the accelerometer capacitance detection circuit is not easily affected by the environmental and own factors, detection results are accurate, and the power consumption is low.

Description

technical field [0001] The invention relates to the field of accelerometer research, in particular to an accelerometer capacitance detection circuit. Background technique [0002] Today accelerometers are widely used in automotive, industrial automation, aerospace and many other fields. Capacitive accelerometers are popular for their low temperature sensitivity compared to piezoresistive accelerometers. In addition, compared with analog accelerometers, digital accelerometers have the advantage of being able to directly perform error correction and compensation without an additional ADC and become the mainstream choice. [0003] figure 2 It is a traditional open-loop accelerometer capacitance detection circuit. In the traditional accelerometer capacitance detection circuit, there are two important modules, the capacitance-voltage converter (C / V) and the voltage-to-digital converter (V / V) of the subsequent stage. D). However, there are three main disadvantages in this comb...

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Problems solved by technology

[0006] The invention provides an accelerometer capacitance detection circuit, which solves the problem that the existing accelerometer capacitance detection circuit is easily affected by the environment and its own

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