有鑑於現今台灣少子化的現象，未來可能會面臨到醫療人力嚴重不足，因此目前趨勢是結合穿戴式醫療裝置、遠端醫療、雲端系統等科技來減輕人力負荷。為了將加速度感測器應用於穿戴式裝置上，本論文實現一單軸電容式加速度感測系統，選用CMOS-MEMS製程設計電容式加速度感測器，並且定期重置電容橋輸出，減少來自感測器電容充放電所造成的輸出偏壓偏移。此外，透過後端處理電路的交流抵補電壓抑制技術，消除前端電容式加速度感測器不匹配所產生之交流抵補電壓，以免在高放大倍率時輸出訊號飽和。藉由將感測器與積體電路整合於單晶片，降低加速規的體積與成本。
本晶片使用台積電(TSMC) 0.35 μm CMOS/MEMS 2P4M 3.3V 混合訊號製程加上微機電後製程製作，以40 S/B 封裝，晶片總面積為2.429×2.068mm2，包含感測器及訊號處理電路。由加速度振動量測平台(Shaker)提供加速度應力，此晶片在±8g的感測範圍下有69.11(mVpp/g)的靈敏度，全系統含感測器的總消耗功率為1.89mW。

Owing to the recent trend of fewer children and more elders in Taiwan, we might face the shortage of the medical personnel in the future. One of the solutions is to combine high technologies, such as wearable devices, telemedicine, and cloud computing, with hospitals, so that it can lessen the burden on caregivers. In order to apply the accelerometer to wearable devices, a single-axis capacitive accelerometer system has been implemented, whose sensor is made by micro-electromechanical system (MEMS) process. The capacitor bridge outputs are reset to dc voltage regularly for reducing the bias voltage drift caused by the undesirable charging and discharging from the capacitive accelerometer. Besides, an ac offset cancellation loop is proposed to suppress the offset voltage originated from the mismatches in the MEMS sensor, so the mismatch-induced offset would not saturate the chip output. The integration of the MEMS sensor and the complementary metal-oxide-semiconductor (CMOS) circuits significantly reduces the instrument size and costs.

The proposed chip, fabricated by Taiwan Semiconductor Manufacturing Company (TSMC) 0.35μm 2P4M mixed-signal standard CMOS process and MEMS post process, consists of the front-end sensor and the back-end signal processing circuits, and it occupies 2.429×2.068-mm2 area. The measured sensitivity is 69.11(mVpp/g) within the ±8g sensing range, and the power consumption of the chip is 1.89mW with a 3.3V power supply.

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