A New Low-Voltage Log-Lin Response CMOS Image Sensor for XGA

• Main Authors: Chien-Ying Wu, 吳建瑩
• Other Authors: Sau-Mou Wu
• Format: Others
• Language: en_US
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/09965570621928024920

碩士 === 元智大學 === 電機工程學系 === 93 === In this thesis, a low-voltage log-lin response CMOS image sensor for XGA is analyzed, designed and implemented in TSMC 0.35μm standard process. The new pixel cell has logarithmic response at low illumination and high output swing as well as linear response at high illumination intensity. It can use the logarithmic response to enhance the minimum detectable photocurrent at low illumination; at high illumination it can detect the maximum photocurrent by adjusting the integration time. In contrast to the conventional pixels, the dynamic range limit and output swing can be improved. Furthermore, this proposed pixel has in-pixel CDS operation to reduce the fixed pattern noise and high sensitivity at low illumination. In the whole image sensor, non-ideality effects have also been considered for XGA application. By theoretical analysis and simulation, we demonstrate that this new CIS pixel owns the logarithmic and the linear characteristics with high dynamic range, high output swing and in-pixel fixed-pattern noise reduction. In particular, it is operating from a single 1.8V supply while realized in a TSMC 0.35μm CMOS 2P4M standard process. For prototyping purpose, an 80x60 and a 128x128 photodiode arrays are implemented. The simulation results are demonstrated for XGA resolution.