| Summary: | 碩士 === 國立暨南國際大學 === 電機工程學系 === 97 === In this thesis, we designed and analyzed front-end readout circuit for linear-array amperometric biosensor. The front-end readout circuit can acquire a large number of sensor signals at one time and can raise signal-to-noise ratio (SNR) when it combines with linear-array sensor. We used commercial blood glucose meter to find the relation between the ranges of current response (0.7u～14uA), sensor resistance(22K~390K ) and concentration measurement(31～550mg/dl). Then, this data was used to build amperometric biosensor equivalent circuit. In the circuit architecture, the amplifier used Folded Cascode structure. The amplifier was integrated with feedback resistance to accomplish transresistance amplifier and the tiny signal current was amplified and changed into signal voltage. At the back of transresistance amplifier was Analog Multiplexers that was used to select signal voltage and is controled by output digital signal. This circuit architecture could reduce circuit area. Besides, the measurement and simulation was done to analysis the not ideal effect of analog multiplexer switch, the relation between sensor resistance and noise, and the circuit noise. We used SPICE to simulate the circuit and used discrete circuit for testing and verification. The circuits were fabricated by using TSMC 0.35um 2P4M CMOS process.
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