Low Power Consumption And High Precision Capacitive Accelerometer System Design And Research

The micro machined accelerometer system is composed of the micro machined accelerometer chip and detection circuit.As a detection device,the micromachined ac-celerometer can be used to measure linear accelerationinertial sensors,like inertial force,angle,vibration and shock.The micromachined accelerometer system is very broad prospects for application in the automotive,consumer electronics,inertial guid-ance.In this paper,the micromachined accelerometer system of capative detection type has some advantages:high sensitivity,good linearity and high stability in a variety of detection in the form of accelerometer to study more.Power consumption of the acce-leration system is essential for its engineering applications, this paper analyzes the acceleration system of power distribution,On the basis of not reducing the system performance by optimizing the circuit design, it reduces power consumption by re-placing higher performance chips.reducing operating frequency.Precision require-ments for the acceleration system,on the basis of analysis of the detection circuit’s noise.then analysis the influence of parameter values of the passive components of the detection circuit module. The studies provides theoretical basis and experience inra-tional design and optimization of capative micromachined acceleration sensor. The work has some relevant significance to future engineering use.The major work of this thesis contains:(1) According to the requirement of the accelerometer with low power consump-tion,the detective circuit is designed.After analyzing the power consumption distribu-tion of accelerometer system.For the different characteristics of the system circuit module,a different approach to optimize the circuit and reduce system power con-sumption.(2) According to the requirement of the accelerometer with high accuracy and large range,the detective circuit is designed.After analyzing the noise performance of parts of accelerometer system,further analysis of the values of the parameters of pas-sive components on the detection circuit module to improve the accuracy of the mi-cromachined accelerometer system.(3) The establishment of the accelerometer system test platform.the accelerome-ter system has been tested.the test show that the equivalent output noise of the analog part of the acceleration system is about16.3ug/(?)Hz. the equivalent output noise of the acceleration system is approximately20ug/(?)Hz.±1g, the linearity of the ac-celerometer system was99.9975%.1.5hours of the accelerometer system stability test results, the sampling rate of2.5MHz, the standard deviation of the demodulator output is0.5mg; sampling rate of40MHz, the demodulator output standard deviation of0.7mg.