單晶磁力-加速度計及介面讀出電路設計

Abstract

本論文提出可在混和訊號微機電製成下，完成加速度計及磁力計及讀出電路設計。磁力計操作範圍在±70µT內，電容變化為±630aF的線性變化，敏感度9aF/µT，而加速度計操作範圍在±5g內，電容變化為±4.5fF的線性變化，敏感度0.9fF/g，利用後段電路讀取此電容範圍，可將靈敏度提升為80mV/g或5.6mV/µT。利用專業微機電設計軟體，具體分析模擬微機電運動行為及電路特性，完成微機電與電路整合設計。讀出電路量測結果，電路靈敏度有1.3mV/aF，其功率消耗為372µW且輸出雜訊為3.48µV/√Hz。單軸磁力計的靈敏度為 8.7nm/µT*mA。

A monolithic accelerometer and magnetometer with integrated capacitance to voltage readout circuit in 0.18um CMOS MEMS process is proposed. The sensing range of the combo sensor is ±5g and ±70µT. The variation of the capacitance is ±4.5fF and ±0.63fF. The sensitivity of the combo is 0.9fF/g and 9aF/µT respectively. The following circuit is a capacitance to voltage readout circuit. The sensitivity of the full system is 80mV/g and 5.6mV/µT. The measurement result of the readout circuit has sensitivity of 1.3mV/aF and power consumption of 372µW. The measurement result of the magnetometer has sensitivity of 8.7nm/µT*mA.