臺灣博碩士論文加值系統

本篇論文提出及分析應用於下視網膜互補式金氧半太陽能電池480像素刺激晶片移植系統，晶片架構基於分區供電方式(DPSS)和主動式像素元件(APS)改良輸出刺激電流之效率。實驗之晶片三十二區分區供電為總數480的光二極體陣列以及控制訊號產生電路。而晶片採用台積電0.18um互補式金氧半CIS製程工藝。最終的晶片尺寸為3.1mm x 3.1mm，起初晶片無法正常運作，但經過電路修改程序後(FIB)，此晶片在 505.4 lux 之訊號光以及94mW/cm2 之紅外線背景光照射下量測，負載為10-kΩ時控制訊號頻率為38赫茲，輸出的雙向刺激電流有9.0uA;負載為生物模型時控制訊號頻率為30赫茲，輸出的雙向刺激電流有9.0uA，累積電荷量為9.8nC。此量測結果驗證了晶片修改過後可以正常操作。

A photovoltaic-cell-powered CMOS 480-pixel implantable chip is proposed for subretinal prostheses. In the proposed chip, the divisional power supply scheme (DPSS) and the active pixel sensor (APS) are adopted to improve the efficiency of output stimulation currents and the image sensitivity. The proposed chip consists of totally 480 photodiode array with 32 DPSS divisions, control signal generator circuits, and photovoltaic cells. It is designed and fabricated in 180-nm CMOS image sensor (CIS) technology. The chip size is 3.1mm x 3.1mm. At first, the chip have not any output function. After FIB, this chip measured frequency of 32-phase control signals is 30 Hz under signal light intensity of 505.4 lux and background IR intensity of 94 mW/cm2. The measured output stimulation current is 9.0 μA under 10-kΩ load. Under the equivalent electrode impedance load, the measured frequency of 32-phase control signals is 38 Hz. The measured peak output stimulation current is 9.0 μA and the amount of injected charges per pixel is 9.8 nC. The measurement results have verified the correct function of the proposed subretinal implant chip after FIB.

ABSTRACT (CHINESE) i
ABSTRACT (ENGLISH) ii
ACKNOWLEDGEMENTS iv
CONTENTS v
TABLE CAPTIONS vii
FIGURE CAPTIONS viii

CHAPTER 1 INTRODUCTION 1
1.1 Background 1
1.2 Review on the Subretinal Prostheses 4
1.3 Motivation 10
1.4 Design Goals 11
1.5 Main Results and Thesis Organization 12
CHAPTER 2 CHIP ARCHITECTURE AND CIRCUIT DESIGN 13
2.1 System And Chip Architecture 13
2.2 Photovoltaic Cell Layout Design 18
2.3 Circuit Design .21
2.3.1 Four Directional Sharing Electrodes (FDSEs) 21
2.3.2 Adaptive Background Cancellation Circuit (ABCC) 26
2.3.3 Pixel Circuit 31
2.3.4 Constant GM, Clock Generator And Level Shifter 33
2.3.5 Control Signal Generation Curcuit 36
2.3.6 Charge Pump Circuit [27] 39
2.3 Post Simulation Results 43
CHAPTER 3 EXPERIMENTAL RESULTS 45
3.1 Measurement Results of Photovoltaic Cell Test-keys 45
3.2 Measurement Results of Subretinal Chips 52
3.2.1 Measurement Setup 52
3.2.2 Measurement Results 55
3.2.3 Discussion 65
3.2.4 Redesign 68
CHAPTER 4 CONCLUSIONS AND FUTURE WORK 70
4.1 Conclusions 70
4.2 Future Work 71
REFERENCES 72
VITA 78

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