臺灣博碩士論文加值系統

由於積體電路科技的發展及醫學的進步，使微小的電子醫療元件得以實現，用於神經生理訊號檢測系統，而可攜式或植入式裝置達到隨時隨地的健康檢測。在生理訊號的檢測系統中，類比前端電路十分重要，它必須要能有效地蒐集並放大生理訊號，並防止雜訊干擾，才能讓整體電路擁有良好的效能表現。
本論文主要針對兩種生理訊號，顱內腦波訊號(ECoG)及電誘發複合活動電位(ECAP)，分別來設計類比前端電路。前者訊號的頻率約在0.5 Hz到100 Hz，振幅大約在0.1 mV到1 mV之間，所以設計的類比前端電路頻寬介於0.5 ~100Hz，具有三段可調的放大增益60.4/70.3/79.3 dB，輸入參考雜訊為0.95 μVrms，雜訊效率因子(NEF)為3.31。類比前端電路具有十六個通道，。此類比前端放大器包含了低雜訊前端放大器、可程式增益放大器、八通道多功器和轉阻放大器，功率消耗為95.2μW，平均每個通道所消耗的功率為5.95μW。後者訊號的頻率約在0.5 Hz到1K Hz，振幅大約在0.1 mV到2 mV之間，而設計的類比前端電路低頻截止頻率小於0.5 Hz、高頻截止頻率具有三段可調在150/606/1.25K Hz，並具有三段可調的放大增益59.8/69.8/79.8 dB，量測頻寬內的輸入參考雜訊為0.85 μVrms，功率消耗為9.0 μW，雜訊效率因子(NEF)約為2.31，為了使電路達到更低的雜訊，此電路使用了截波調變技術來移除電路本身在頻寬內的雜訊，並有三個回授電路，用以消除不理想效應。此類比前端電路由台灣積體電路製造股份有限公司製造以0.18微米製程實現。

This paper presents a 16-channel analog front-end (AFE) acquisition circuit for ECoG recording systems and a one channel analog front-end (AFE) acquisition circuit for ECAP recording systems. The former one consists of a 16 channel analog front-end amplifier (AFE Amplifier). The AFE Amplifier consists 16 analog front-end blocks, a 16-to-1 multiplexer, a trans-impedance amplifier (TIA). The latter one consists a chopper modulation low-noise preamplifier and Switched-Capacitor low-pass filter(SC-filter) and Switched-Capacitor amplifier (SC-Amp). They are designed for amplification and filtering the biopotential signals, these biopotential signals have the characteristics of small amplitudes, low frequency.
The AFE acquisition circuits which is fabricated in TSMC 0.18μm CMOS process can adjust gain at three steps (60.4/70.3/79.3dB) and (59.25/69.28/79.3dB) digitally, the high-pass corner can achieve as low as 0.5Hz and low-pass corner of former one can achieve 113 Hz, low-pass corner of latter one can adjust gain at three steps (150/606/1.25K) digitally. The input-referred noise is 0.95μVrms and 0.85μVrms. The noise efficiency factor is 3.31 and 2.31 of low-noise preamplifiers. The whole AFE acquisition circuit power consumption of former one is 95.2μW where 5.95μW per channel. The latter one is 73.4μW per channel.

摘要 I
Abstract II
Acknowledgements IV
Contents V
Figure Captions VII
Table Captions XIII
Chapter 1 Introduction 1
1.1 Background 1
1.2 Review on Analog Front-End 6
1.2.1 Review on ECoG AFE Amplifier without choppers 9
1.2.2 Review on ECAP AFE Amplifier 13
1.3 Motivation 15
1.4 Main Results and Thesis Organization 18
Chapter 2 Design of an Analog Front-End ECoG Acquisition Circuit 21
2.1 Design Consideration 23
2.1.1 Circuit Design Consideration 25
2.2 Analog Front-End Circuit Design 26
2.2.1 Low-Noise Pre-amplifier 28
2.2.2 Programmable Transconductance Gain Amplifier(PTGA) and Multiplexer 41
2.2.3 Trans-impedance Amplifier(TIA) 43
2.3 Post-Layout Simulation Results of AFE 47
Chapter 3 Design of an Chopper-Stabilized Analog Front-End ECAP Acquisition Circuit 52
3.1 Design Consideration 53
3.2 Chopper-Stabilized Analog Front-End Circuit Design 55
3.2.1 Inverter-Based Folded-Cascode Amplifier 58
3.2.2 Hybrid DC Servo Loop 60
3.2.3 Ripple Reduction Loop and Positive Feedback Loop 68
3.2.4 Stability Analysis of CCCIA 71
3.2.5 Switched-Capacitor 1st Order Low Pass Filter and Switched-Capacitor Amplifier 74
3.3 Post-Layout Simulation Results of Chopper-Stabilized AFE Amplifier 78
Chapter 4 Experimental Results 86
4.1 Chip Layout Descriptions 86
4.2 Measurement Setup 87
4.2.1 ECoG AFE Amplifier Measurement Setup 87
4.2.2 ECAP AFE Amplifier Measurement Setup 95
4.3 Measurement Results 101
4.3.1 ECoG AFE Amplifier Measurement Results 101
4.3.2 ECAP AFE Amplifier Measurement Results 107
4.4 Discussion of AFE acquisition circuit 115
4.4.1 Discussion of ECoG AFE Amplifier 115
4.4.2 Discussion of ECAP AFE Amplifier 118
4.4.3 Redesign of ECAP AFE Amplifier 120
Chapter 5 Conclusion and Future Work 127
5.1 Conclusion 127
5.2 Future Work 129
References 131

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