Modeling random telegraph signal noise in CMOS image sensor under low light based on binomial distribution

• Published in: Chinese physics B Vol. 25; no. 7; pp. 164 - 170
• Main Author: 张钰 逯鑫淼 王光义 胡永才 徐江涛
• Format: Journal Article
• Language: English
• Published: 01.07.2016
• Subjects: CMOS图像传感器; MOSFET; 二项式分布; 低照度; 信号噪声; 源极跟随器; 统计模型; 随机电报信号
• ISSN: 1674-1056; 2058-3834
• DOI: 10.1088/1674-1056/25/7/070503

The random telegraph signal noise in the pixel source follower MOSFET is the principle component of the noise in the CMOS image sensor under low light. In this paper, the physical and statistical model of the random telegraph signal noise in the pixel source follower based on the binomial distribution is set up. The number of electrons captured or released by the oxide traps in the unit time is described as the random variables which obey the binomial distribution. As a result,the output states and the corresponding probabilities of the first and the second samples of the correlated double sampling circuit are acquired. The standard deviation of the output states after the correlated double sampling circuit can be obtained accordingly. In the simulation section, one hundred thousand samples of the source follower MOSFET have been simulated,and the simulation results show that the proposed model has the similar statistical characteristics with the existing models under the effect of the channel length and the density of the oxide trap. Moreover, the noise histogram of the proposed model has been evaluated at different environmental temperatures.