一种新型低噪声真空微电子加速度计的接口ASIC

摘要

真空微电子加速度计基于隧道效应而工作,其内部固有的低频噪声(如1/f噪声)大大降低其信噪比,而且也是影响精度和线性度的主要因素.采用混频技术和相关检测算法,本文研制和设计了一种新型低噪声接口ASIC(专用集成电路).最后测试了加速度计的噪声和线性度,在0～200 Hz范围内输出信号平均噪声密度为69μV·Hz-1/2,线性度相关系数为99.99％,最大的非线性度为0.41％.通过实验结果可以看出该电路能大大改善加速度计的噪声特性和线性度,而且该电路设计思想能用于其它隧道效应加速度计.%Abstract:The vacuum microelectronic accelerometer works based on tunneling effect,the inherent low frequency noise such as 1/f noise decreases the signal-to-noise ratio greatly,and it is the main influencing factors to precision and linearity of accelerometer.In order to eliminate the noise and improved the linearity characteristic, in this paper a novel low noise interface ASIC ( Application Specific Integrated Circuit) was bring forward and designed according to the frequency mixing technique and coherent detection technology.Finally the noise and linearity of the accelerometer was tested,the mean noise spectrum density of output signal is 69μV · Hz-1/2 from 0 Hz to 200 Hz.the correlation coefficient of the least-square linear fitting curve is 99.99％,the maxim nonlinearity is 0.41％.Through the results and compare with the previous results of circuit,we can draw conclusion that the noise and linear performs have been improved through interface circuit,and furthermore,the idea of circuit design can also be used to the other tunneling accelerometer.