A dynamic range extension scheme applied to a TDI CMOS image sensor  

作　　者：徐超 姚素英 徐江涛 高志远 韩立镪 

机构地区：[1]School of Electronic Information Engineering,Tianjin University

出　　处：《Journal of Semiconductors》2014年第2期86-91,共6页半导体学报（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Nos.61036004,61076024)

摘　　要：A dynamic range extension scheme applied to a time delay integration （TDI） CMOS image sensor （CIS） is presented. Two types of pixels with higher and lower conversion gain are adopted in the pixel array, which are suitable for capturing images in low and high illumination respectively. By fusing the two kinds of pixels＇ output signals in the process of TDI accumulation, a high dynamic range image can be achieved. Compared with the traditional multiple integration technique, no photoelectrons generated during the exposure time are discarded by the reset operation, and thus a higher level of signal-to-noise ratio （SNR） can be retained. A prototype chip with an 8 × 8 pixel array is implemented in a 0.18 μm CIS process, and the pixel size is 15 × 15 μm2. Test results show that a 76 dB dynamic range can be achieved in 8-stage TDI mode, when the SNR boost can reach 7.26 dB at 90.8 lux.A dynamic range extension scheme applied to a time delay integration （TDI） CMOS image sensor （CIS） is presented. Two types of pixels with higher and lower conversion gain are adopted in the pixel array, which are suitable for capturing images in low and high illumination respectively. By fusing the two kinds of pixels＇ output signals in the process of TDI accumulation, a high dynamic range image can be achieved. Compared with the traditional multiple integration technique, no photoelectrons generated during the exposure time are discarded by the reset operation, and thus a higher level of signal-to-noise ratio （SNR） can be retained. A prototype chip with an 8 × 8 pixel array is implemented in a 0.18 μm CIS process, and the pixel size is 15 × 15 μm2. Test results show that a 76 dB dynamic range can be achieved in 8-stage TDI mode, when the SNR boost can reach 7.26 dB at 90.8 lux.

关 键 词：CMOS image sensor time delay integration dynamic range extension digital domain 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置] TN792[自动化与计算机技术—控制科学与工程]