摘 要
　　CMOS影像感測器與電荷耦合元件(Charge Couple Device CCD)相較，具有晶片整合、低功率、低成本與面積的優點。一般CMOS影像感測器的動態範圍(Dynamic Range)(約60dB)不足以捕獲真實世界完整的亮度範圍(超過100 dB)。有幾種利用控制時間的方法來增加動態範圍，然而這些方法無法增加最高的訊號雜訊比(Peak Signal-to-Noise)。
　　本論文中，我們設計一個可增加動態範圍與訊號雜訊比的CMOS影像系統，此系統使用像素(Pixel)層級類比數位轉換器(Analog-to-Digital Converter)，且所讀出的數位訊號具有高速的特性。我們利用TSMC CMOS 0.18 μm 製程來製作影像感測器，經模擬動態範圍及訊號雜訊比同時都可以獲得增加。

Abstract
　　CMOS image sensors have some advantages compare with Charge-Coupled Device (CCD) that are on-chip functionality、 system power reduction、 cost and area. Typical CMOS image sensors do not have sufficient Dynamic Range (DR) (around 60 dB) to capture the full range of illumination in the real world (over 100 dB). To increase DR, several methods have been proposed using the time as a control variable. However, these methods do not increase peak Signal-to-Noise Ratio (SNR).
　　In this paper, we design a high DR and SNR CMOS imaging system which using pixel level Analog-to-Digital Converter (ADC), and digital data is read out at high speeds.[23] We intend to develop an image sensor by using TSMC CMOS 0.18 μm technology. Consequently, DR and peak SNR are increased simultaneously.

CONTENTS
ABSTRACT
CONTENTS
LIST OF FIGURES
LIST OF TABLES

CHAPTER 1 Introduction……………………………………………………………………… 1
1.1 Historical Background……………………………………………………………… 1
1.2 The Motivation.……………………………………………………………………… 5
CHAPTER 2 Photodetectors…………………………………………………………………… 6
2.1 Introduction ………………………………………………………………………… 6
2.2 Charge Couple Device ………………………………………………………………11
2.3 CMOS Image Sensor……………………………………………………………………14
2.3.1 Passive Pixel Sensor (PPS) ……………………………………………………15
2.3.2 Active Pixel Sensor (APS)………………………………………………………17
CHAPTER 3 High dynamic Range Image Sensor ……………………………………………21
3.1 Dynamic Range and SNR in the Integration Mode………………………………21
3.2 Dynamic Range Enhancement Methods………………………………………………24
3.2.1 Enhancing Dynamic Range by Adjusting Well Capacity ……………………25
3.2.2 Enhancing Dynamic Range Via Multiple Sampling……………………………27
3.2.3 Time to Saturation ………………………………………………………………29
3.2.4 Asynchronous Self-Reset with Multiple Capture……………………………31
3.2.5 Synchronous Self-Reset with Residue Readout………………………………33
3.3 Adaptive Sampling Method.…………………………………………………………35
CHAPTER 4 Implementation..…………………………………………………………………40
4.1 Pixel Design …………………………………………………………………………40
4.2 Sense Circuit…………………………………………………………………………42
4.3 Address Decoder………………………………………………………………………45
4.4 Image Sensor Design…………………………………………………………………46
CHAPTER 5 Experimental Results……………………………………………………………51
5.1 Adjusting well capacity……………………………………………………………51
5.2 Multiple sampling……………………………………………………………………52
5.3 Time to saturation …………………………………………………………………54
5.4 Adaptive Sampling Method …………………………………………………………54
5.5 Pixel Simulation ……………………………………………………………………56
5.5.1 The effect of process variance for circuit ………………………………58
5.5.2 The effect of temperature variance for circuit …………………………60
5.5.3 The effect of voltage variance for circuit ………………………………62
CHAPTER 6 Conclusions ………………………………………………………………………64
REFERENCES ………………………………………………………………………………………65

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