Abstract: A new structure of time-divided closed-loop accelerometer is proposed. It requires only one operational amplifier as a negative-coefficient PID is just sufficient. This structure not only reduces the area consumption of the whole chip of the readout circuit, but also lowers the equivalent input noise acceleration as one operational amplifier and two large resistors are reduced. The readout circuit is fabricated using 0.35 μm HV CMOS process, with self-test function included. Test results show that the linearity of 99.72% is achieved under self-test mode. The root-mean-square output noise voltage is around 140 μV from DC to 200 Hz.

Key words: proportional integral derivative controller, closed-loop, accelerometer, self-test function, microelec- tromechanical systems

摘要： 提出一种改进结构的时分反馈闭环加速度计, 该结构使用负系数的PID控制器, 只需要一个运算放大器。改进后的结构减小了读出电路的芯片面积, 同时省去一个运算放大器和两个大电阻, 因此能降低系统噪声。读出电路采用0.35 μm高压CMOS工艺, 并包含自检测功能。测试结果显示, 在自检测模式下, 闭环加速度计的线性度为99.72%。在DC到200 Hz内, 输出噪声电压均方根值约为140 μV。

关键词: 比例积分微分控制器, 闭环, 加速度计, 自检测, 微机电系统