通过实验分析了电容读取芯片MS3110P各项性能指标,并设计了一款能自适应匹配模拟开关产生的电荷注入效应的P控制器;开发出一款具有单电容阵列测量模式和差分电容阵列测量模式的微电容阵列检测电路,并探讨了其寄生电容产生的原因。测试结果表明,该检测电路克服了各种寄生电容对传感器的影响,提高了测量精度,能够应用于MEMS触觉传感器微电容阵列的测量。
In view of the capacitance reading chip MS3110P has the internal programmable capacitor array that can be used for matching the capacitance error derived from the analog switches, this article analyzes the various performance indicators based on the experiments. A P controller used to match the charge injection effect conducted by the analog switch has been designed. The micro-capacitor array detection circuit owning the function of single capacitance array measurement mode and differential capacitance array measurement mode has been designed. Besides, causes of parasitic capacitance have been discussed. The experimental results have demonstrated the designed circuit overcame the impact of various parasitic capacitances on sensor and enhanced the measuring accuracy. It could also meet the needs of the measurement requirements of micro-capacitor array for MEMS sensors.