【作者】 林伟俊；

【导师】 金仲和；

【作者基本信息】 浙江大学 ， 微电子与固体电子学， 2010， 硕士

【摘要】 加速度传感器是一种重要的惯性传感器,它被广泛地运用在惯性导航、消费电子、汽车电子和地质勘探等各个领域。硅微机械加速度计作为一种可以测量加速度的传感器,可分为压电式、隧道式、压阻式和电容式等。其中电容式微机械加速度传感器具有分辨率高、动态范围大、温度特性好等优点,从而得到了广泛的应用。电容式微机械加速度系统由加速度敏感元件和电容检测电路组成,因此电容检测电路的性能直接影响了电容式微机械加速度系统的整体性能,提高电容检测电路的性能是电容式微机械加速度系统设计中一个十分重要的部分。本文针对变面积电容式微机械加速度计,设计了单路载波调制型检测电路,并对其工作原理进行了分析,对电路的温度特性进行了分析和测量,最后对MEMS三轴加速度计的检测电路进行了小型化和工程化工作。本论文主要工作如下:（1）设计了单路载波调制型电容检测电路,包括载波发生模块,带通滤波模块,电荷放大模块,仪表放大模块,移相模块,同步解调模块,低通滤波模块,分析了各个模块的工作原理和限制因素。（2）针对单载波调制型检测电路,分析了各个模块的参数变化和PCB板的寄生效应等因素对检测电路的影响对系统的影响;同时重点分析了温度变化对系统的影响;针对实验室以前的单轴加速度计的检测电路受温度的影响而容易发生漂移的缺点,从降低系统功耗和改善系统热设计两个方面入手,设计了三轴加速度计的检测电路。（3）参考加速度计相关测试标准,制定了加速度计性能测试方案,建立了测试平台。根据该方案,对加速度计系统性能进行了全面的测试。测量结果表明:加速度计的标度因数为115.43mV/g,一小时之内的零偏稳定性为2.254*10^-4g,启动时间约为1500s,阈值约为0.12mg,分辨率约为0.1mg,-1g～+1g的线性度为99.999%,带宽约为140Hz。更多还原

【Abstract】 Accelerometer is a kind of important inertial sensor that can be used in inertial navigation, consumer electronics, motor electronics and geologic exploration. Silicon micro-accelerometer can measure the acceleration of the movement, and there are many kinds of Micro-accelerometer based on piezoelectric, tunnel, piezoresistive, capacitive effect.Capacitive MEMS micro-accelerometer is widely used because of its high resolution, large dynamic range and low temperature drift. Capacitive MEMS accelerometer consists of acceleration sensor and capacitance detection circuit. The performance of capacitance detection circuit has a direct impact on the performance of accelerometer system. The improvement of capacitance detection circuit performance is important in determining the performance of accelerometers.A single carrier modulation capacitance detection circuit is designed for an area changing type capacitive MEMS accelerometer. The principle of this circuit is analysed, and temperature characteristics of this circuit is analysed and measured, at last miniaturization and engineering of triaxial MEMS accelerometer was finished.The major work of this thesis contains:（1） A single carrier modulation capacitance detection circuit consisting of DDS module, BFP module, charge amplifier module, instrument amplifier module, active phaser module, synchronously demodulation module and LPF module was designed, while operation principle and constraining factor of every module was anlysed, and parameter of every module was figured out according to theory.（2） According to single carrier modulation detection circuit, the parameter of every module and the influence of PCB board parasitic effect was figured out. The impact of temperature on accelerometer system was also analysed minutely. Duing to temperature drift of previous accelerometer system, a new triaxial MEMS accelerometer system was design which has lower power consumption and better heat emanation design. （3） A performance test scheme was made with reference to test guides on accelerometers. The measurement shows that capacitive MEMS accelerometer has asensitivity of 115.43mV/g, zero-draft of 2.246*10^-4g. Start-Up time of 1500s,threshold value of 0.12mg , resolution of 0.1 mg, linearity of 99.999% and bandwidthof 140Hz.更多还原