本論文提出一個可結合並應用於生醫領域的電化學感測器。此電路前端由一個電流鏡與可自動偵測電流範圍之電路組成，用以提升可量測之電流範圍。此電路可以整合於外部的生醫感測系統且符合其要求的規格。此架構的電流量測原理為定電壓量電流法，採用電流傳輸器使感測端的電壓穩定，接著以電流時間轉換器將電流轉換為時間訊號，再以時間數位轉換器輸出十位元的數位碼。透過此機制，將電流值轉換為可顯示之數位訊號。整體設計著重於降低電路複雜度，有效減小佈局面積，使生醫感測系統微小化。
本電路以TSMC 0.18-μm 1P6M CMOS製程來模擬設計，供應電壓為1.8 V，以100 MHz之時脈訊號驅動。量測結果顯示功率消耗為1.41 mW。此外，可感測之電流範圍亦達到20 ~ 1200 µA，且具良好線性度，R平方之平均值為0.9986。

This thesis presents a mechanism of current sensing for biomedical applications. This work can be integrated with external biomedical system, and to meet the requirement of the specification, by using a current mirror with an automatic current range detection circuit to increase the current sensing range. A method of constant voltage current measurement is utilized, and applies a current conveyor to maintain the voltage at sensor terminal. Follow by a current-to-timer converter to process the current output from current mirror, and transfer the sensor current into time signal. Then apply a time-to-digital converter to obtain 10-bit digital code. Therefore, Current signal can be displayed in digital mode. The overall design focuses on reducing circuit complexity, effectively lessens layout area, miniaturization of the whole biosensor system can be realized. The proposed circuit is implemented in TSMC 0.18-μm 1P6M CMOS technology. The driven clock signal of circuit is 100 MHz with a supply voltage of 1.8 V. The power dissipation is approximate to 1.41 mW. The measured current range achieves from 20 µA to 1200 µA and has good linearity with average R-squared value of 0.9986.

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