电容式加速度计的数字化处理电路及其与模拟电路的比较  

A Comparison between Analog and Digital Capacitive Accelerometer

作　　者：林伟俊[1] 胡世昌[1] 郑旭东[1] 王昊[1] 金仲和[1] 

机构地区：[1]浙江大学信息与电子工程系,杭州310027

出　　处：《传感技术学报》2009年第11期1562-1567,共6页Chinese Journal of Sensors and Actuators

基　　金：国家重点基础研究发展计划(973计划)资助(2006CB300405)

摘　　要：介绍了对一种电容式MEMS加速度计处理电路的数字化工作,并对数字式加速度计系统的各个组成模块进行了分析,并与模拟处理电路的相应模块进行比较,给出了制约数字和模拟加速度计性能的因素。实验测试结果表明,数字式加速度计的零偏稳定性达到了0.21mgn,相对模拟加速度计的零偏稳定性(1.02mgn)提高了约5倍,噪声降低了3/5,数字式加速度计系统的性能有了很大的改进。这是由于数字系统采用了先进的解调算法,使得载波的信噪比有所提高,相位噪声有所降低。A digital processing system based on a capacitive MEMS accelerometer is introduced. Each part of the digital processing system is carefully analyzed and makes a comparison with the analog processing system. Restricting factors of both analog and digital accelerometer systems are given. The test result of the digital accelerometer system turns out that the bias stability is 0.21 mgn ,five times better than the analog aecelerometer system（1.02 mgn）. The noise of the digital accelerometer system is reduced to two fifths compared with the analog accelerometer system. All the results indicate the great improvement of the digital accelerometer system, and the reason of the improvement is due to the advanced demodulation algorithm being applied which results in a higher SNR and a lower phase noise.

关 键 词：微电子机械系统 加速度计 直接数字频率合成 现场可编程门阵列 相位噪声 

分 类 号：TP212.1[自动化与计算机技术—检测技术与自动化装置]