激励电压对梳齿式加速度计系统的影响

为优化梳齿式微硅加速度计的系统设计,研究了激励电压对加速度计性能和电路参数选择的影响。推导出的系统静电力方程说明,激励电压对静电力的影响相当于在预载电压上叠加了微幅高频干扰,该干扰决定了加速度计的标度因数稳定性。由闭环传递函数得出了标度因数稳定性与电路参数间的关系。实验结果表明,根据标度因数稳定性指标选取了合适的电路参数后,可以忽略激励电压对静电力的影响。在实际应用中,利用该结论可以减小加速度计尺寸并降低功耗。

Effects of excitation voltage on comb-finger accelerometer system

The design of a comb-finger micro silicon accelerometer was optimized by analyzing the effects of the excitation voltage on the accelerometer performance and the selection of the circuit parameters. The electrostatic force equation shows that the effect of the excitation voltage on the electrostatic force is equal to a small-amplitude high-frequency noise which determines the accelerometer scale factor stability. The relationship between the scale factor stability and the circuit parameters was derived from the closed-loop system transfer function. The experimental results show that the effect of the excitation voltage on the electrostatic force can be neglected when the appropriate circuit parameters are chosen based on the scale factor stability. This conclusion can be used to minimize the size and power consumption of accelerometers.