| Summary: | 碩士 === 國立臺南大學 === 電機工程學系碩士班 === 100 === In this thesis, a voltammetry poteneiostat chip, which is adapted for large dynamic range current measurement, is proposed and fabricated for the signal processing of electrochemical biosensors. By combining with different biosensors, the measured current signal shows the detected data for biologic. The proposed chip is designed by integrated circuit technology. In the future, the small-sized and low cost consumer biosensor can be developed.
On circuit design, current range detector will detect the currents which measured by voltammetry potentiostat at first phase. Then decide the scale ratio of multi-ratio current mirror. In second phase, the measured current is scaled into proper magnitude and converted to pulse waveform which frequency is proportional to magnitude of scaled-current. The original sensor current can be calculated by collecting the pulse waveform and the scale ratio indicator.
The integrated potentiostat is designed and fabricated by TSMC 0.35um CMOS process. The specifications of the proposed chip are as follows: the valid sensor current is range from 5nA to 1.2mA, the potential of electrochemical working diode is 1.2V. The current resolution for each ratio: 5nA - 10μA is 80pA, 10μA - 100μA is 830pA, 100μA - 1mA is 8.1nA and 87nA for which higher than 1mA. The power supply voltage is 5V. All functions are fully tested and verified.
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