本篇論文主要目的在於研究生醫感測器之自動化多通道訊號檢測電路及系統設計與實現。整個設計流程從了解原理、電路設計及模擬、實體佈局、量測系統的建構及量測結果,在本論文中均有詳述。 論文中所設計的電路方塊包含以軌對軌為架構之互補式金氧半運算放大器、橋式源極浮接型氫離子訊號檢測電路以及介紹自動化量測所使用到的圖控式虛擬儀表。本研究所設計之軌對軌運算放大器之特性量測,操作於5V時,開迴路增益可達93 dB,功率消耗為7.45mW,偏移電壓約在4.1mV,共模電壓輸入範圍與電壓輸出擺幅約可達到正電源與負電源的範圍。 由本論文所設計之軌對軌運算放大器組成橋式源極浮接型氫離子訊號檢測電路結合一個Ag/AgCl參考電極形成一恆壓恆流檢測電路。另外結合圖控式虛擬儀表所設計出的量測系統進行溶液氫離子酸濃度感測。實驗結果顯示本研究所設計系統在氫離子濃度pH2至pH12之範圍內離子場效電晶體之靈敏度呈現可接受的線性反應,證明此電路具有實用之生醫感測潛力。 本論文所有的積體電路晶片實現是採用聯華電子(UMC) 0.5μm CMOS DPDM的製程技術製作完成。
The reliability, stability and linearity of the sensor signal readout are greatly improved by using the sensor array configuration. With the advantages of small size, reliability, rapid time response, compatible with standard CMOS technology and on-chip signal processing, ISFET based transducers become more important applications in physiological data acquisition and environment monitoring. Therefore, to develop an automatic data acquisition systems on multiple ISFETs become more valuable and important. The objective of this paper presents the design and implementation of a multi-channel bridge-type floating source circuit with self-developed rail-to-rail op amp for H+ sensing applications. The design concerns were focused on self-developed ASICs, multi-channel bridge-type floating source readout circuit, and the automatic data acquisition system with virtual instrument LabVIEW. This architecture shows that all ISFETs are under operation, but only one reference electrode is used. The proposed rail-to-rail op amplifier has been fabricated in UMC 0.5μm double-poly double-metal CMOS technology. Experimental results show with a 5V power supply, the rail-to rail operational amplifier presents a DC gain of 93dB, power dissipation of 7.45mW, offset voltage of 4.1mV and rail-to-rail common-mode input voltage range and voltage output swing. Furthermore, the multi-channel bridge-type floating source configuration built by the proposed rail-to-rail amplifier can perform to collect and calibrate the signal by using LabVIEW, and the measured data are a statistical material in computer. The measured data including drift, sensitivity and hysteresis are satisfied with the sensor characteristics. In a word, the proposed system has the good capability in bio-chemical applications.