硅微谐振加速度计的温度特性

Temperature characteristic of silicon resonant accelerometer

硅微谐振加速度计以其小体积、低成本和高精度的频率信号输出,成为硅微惯性传感器研制的热点之一。温度特性是影响硅微谐振加速度计精度水平的重要因素。在分析硅微谐振加速度计工作机理的基础上,从结构设计方法、工艺流程加工和闭环控制回路方面分析了温度对零位和标度因数的影响因素,同时给出了相应解决措施。研制的硅微谐振加速度计基频约为17 kHz,标度因数约220 Hz/g,在-40～+70℃范围内,谐振频率的温度系数为-71.5×10-6/℃,标度因数的温度系数为-610×10-6/℃,样机在常温下谐振频率的相对稳定性为0.313×10-6,1.5 h零偏稳定性达到42.5μg。

The silicon resonant accelerometer（SRA） is one of research hotspots of inertial instrument for it is small volume,low cost and takes quasi-digital signal as output.The temperature characteristic is one of the important factors that influence the performance of the silicon resonant accelerometer.In this paper,the relationship between the temperature effect and the design of structure and closed-loop control circuits was studied,and the theory and the corresponding solutions were introduced.The natural frequency of the designed accelerometer is 17 kHz with a scale factor of 220 Hz/g.Within-40℃-＋70℃,the temperature coefficient of natural frequency and scale factor are-71.5×10^-6/℃ and-610×10^-6/℃ respectively,and the stability of frequency and bias are 0.313×10^-6and 42.5 μg respectively.