MEMS振动传感器自检测技术研究

发布时间：2018-03-02 01:36

本文关键词： 自检测 MEMS振动传感 sigma-delta模数转换　出处：《哈尔滨工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：几十年积累的大量设计经验与不断提升的制造工艺水平促成了 MEMS振动传感器研究成果的快速更新。同时,这些成果也渗透到了军品与民品等诸多应用领域。与之相比,振动传感器的检测技术发展相对滞后,且传统检测方法已无法适应现在快速精准的检测需求。在此背景下,本课题设计出一种可实现自检测功能的振动传感器系统。自检测模块使用纯数字方法构建激励产生模块,以产生用于传感器系统静态和动态参数检测的正弦信号,激励产生模块与接口电路制造在同一块芯片上。通过数字谐振器产生多位正弦波,该信号流经sigma-delta调制器转化成一位码流,再以静电力反馈的形式作用在传感器敏感单元上,从而转换成等效检测加速度信号。sigma-delta调制器内嵌在谐振器中,以减小芯片面积和计算时间。通过调节信号发生器的参数,正弦信号的幅度和频率可以精确确定,以适应不同的静态和动态参数的测试。为验证自检测模块的适用性,本课题设计了一款振动传感器的闭环sigma de型数字接口电路。电路整体采用非限制性结构来降低系统参数获取难度。同时引入相位补偿器保证稳定性。在分析系统中主要失真源的基础上,对电荷放大器、跟随缓冲器、相位补偿器、积分器、量化器、时序控制电路等子模块进行晶体管级电路设计。利用SpectreVerilog对电路进行数模联合仿真,接口电路信号带内输出噪声密度小于250nV/Hz~(1/2),谐波失真小于-120dB,总体信噪比为103.6dB,性能满足需求。同时自检测模块工作正常,最小可检测到45μg的振动加速度信号,检测范围-0.7g～+0.7g。
[Abstract]:Decades of accumulated design experience and increasing manufacturing technology have contributed to the rapid updating of the research results of MEMS vibration sensors. At the same time, these achievements have also penetrated into many application fields, such as military and civilian products. The detection technology of vibration sensor is lagging behind, and the traditional detection method can not meet the needs of rapid and accurate detection. In this paper, a vibration sensor system which can realize the function of self-detection is designed. The self-detection module uses the pure digital method to construct the excitation generation module to generate sinusoidal signals for the static and dynamic parameter detection of the sensor system. The excitation generation module is manufactured on the same chip as the interface circuit. The digital resonator generates a multi-bit sine wave, which flows through the sigma-delta modulator into a bit stream, and then acts on the sensor sensitive unit in the form of hydrostatic feedback. In order to reduce the chip area and calculate time, the amplitude and frequency of sinusoidal signal can be determined accurately by adjusting the parameters of the signal generator. In order to adapt to the test of different static and dynamic parameters, to verify the applicability of the self-detection module, In this paper, a closed loop sigma de digital interface circuit for vibration sensor is designed. The whole circuit adopts unrestricted structure to reduce the difficulty of obtaining system parameters. At the same time, phase compensator is introduced to ensure stability. On the basis of the main distortion sources, The transistor level circuit is designed for charge amplifier, follower buffer, phase compensator, integrator, quantizer, timing control circuit and so on. The circuit is simulated by SpectreVerilog. The in-band output noise density of the interface circuit is less than 250nV / Hz / 2, the harmonic distortion is less than -120dB, the overall signal-to-noise ratio is 103.6 dB, and the performance of the self-detection module is normal, the minimum vibration acceleration signal of 45 渭 g can be detected, and the detection range is -0.7g ~ 0.7g.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP212

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