Front end circuit of accelerometer and processing method of acceleration signal

Abstract

The invention relates to a front end circuit of accelerometer and a processing method of acceleration signal. The front end circuit is used to connect an acceleration sensor to obtain an original analog signal, and performing front end processing on the original analog signal. The front end circuit comprises: an amplifying circuit, which configured to be connected to the acceleration sensor to receive the original analog signal, and amplify the original analog signal; a low-pass filter circuit, which connected to the amplifying circuit for performing low-pass filtering processing on the amplified signal to eliminate noise. The amplifying circuit comprises: a first chopper circuit, which configured to be connected to the acceleration sensor to receive the original analog signal, and performa first chopping process on the original analog signal; an operational amplifier circuit, which connected to the first chopper circuit to amplify the output signal of the first chopper circuit; a second chopper circuit, which connected to the operational amplifier circuit to perform the second chopping process on the amplified signal. The noise in the front end circuit is small.

Description

technical field [0001] The invention relates to the technical field of acceleration sensors, in particular to a front-end circuit of an accelerometer and an acceleration signal processing method. Background technique [0002] MEMS accelerometers are accelerometers manufactured using MEMS technology. Due to the use of micro-mechanical technology, it has the advantages of small size, light weight and low power consumption. Widely used in vibration detection, orientation detection, consumer applications, motion recognition and other fields. [0003] Piezoresistive accelerometers are made using the piezoelectric effect of PZT (lead zirconate titanate) ceramics. When PZT ceramic is stressed, its resistance value changes. By connecting the piezoresistor bridge, the change of resistance value is converted into the change of voltage. It detects, amplifies and corrects through a special ASIC, and then outputs a binary digital signal corresponding to the acceleration value. [00...

AI Technical Summary

Problems solved by technology

[0006] The analog front end of the traditional accelerometer does not remove the low-frequency 1 / f noise and the input offset voltage (offset), so that the signal-to-noise ratio of the output signal is not high

In addition, in a continuous system, since the sensor and the control circuit are always in a continuous working state, the power consumption is large

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