Digital differential micro-accelerometer

Abstract

The invention relates to a digital differential micro-accelerometer chip which comprises a silicon substrate and two quartz double-end fixing tuning forks, wherein the silicon substrate has the functions of a mass block and a spring; the silicon substrate is composed of the mass block and two cantilever beams for supporting the mass block; a mass block-spring system composed of the mass block and the cantilever beams means the cantilever beams have elasticity along a sensitive direction of the micro-accelerometer chip and the cantilever beams are arranged along one diagonal direction of the mass block; the quartz double-end fixing tuning forks are arranged along the other diagonal direction of the mass block; and the two quartz double-end fixing tuning forks with same structures are arranged in a differential form. The digital differential micro-accelerometer chip can eliminate the influence of temperature on a sensor, can increase the degree of nonlinearity of the sensor and has the advantages of high response speed and high precision.

Description

technical field [0001] The invention belongs to the technical field of micro-mechanical electronics (MEMS) digital accelerometers, and in particular relates to a digital differential micro-accelerometer. Background technique [0002] The digital accelerometer does not need a digital-to-analog conversion link, and can be directly embedded in a digital processing system. It has the advantages of high precision, fast response, and strong anti-interference ability. At the same time, the micro-digital accelerometer processed by micro-mechanical electronic technology has the advantages of small size and low cost, and is attracting more and more attention. The digital micro-accelerometer has a micro-vibration element in the sensor to sense the acceleration. With the corresponding excitation circuit, the vibration element is always in a resonant state. The vibration frequency of the vibrating element is related to the axial force it receives. Through the corresponding mass-spring ...

AI Technical Summary

Problems solved by technology

Due to the different thermal expansion coefficients of quartz and silicon, when the temperature changes, thermal stress will appear in the quartz tuning fork, causing the output of the sensor to drift

In order to solve this problem, in the Chinese patent ZL201210568654.5, titled "Silicon-based Quartz Acceleration Sensor with Temperature Isolation Structure", a temperature isolation structure is proposed to reduce the influence of temperature, but the mentioned temperature isolation The structure reduces the sensitivity of the sensor while effectively reducing the influence of temperature

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