Characteristics of random telegraph signal noise in time delay integration CMOS image sensor

A statistical model based on large sample simulation is established to study the relationship between random telegraph signal (RTS) noise and the number of time delay integration (TDI) stages in TDI CMOS image sensor (CIS). Matlab simulation results show that the mean value of RTS noise increases by a factor greater than M0.5 when the number of TDI stages is M, and the factor approximates to M0.5 with larger TDI stages. In noise histogram, RTS noise exhibits Gaussian distribution when the number of TDI stages is more than a special value. These results serve as a guideline for the design of TDI stages and the analysis of noise.

Large samples are simulated to get the RTS noise histogram. Curve A–G correspond to 1, 2, 4, 8, 16, 32 and 64 TDI stages respectively. Curve A actually represents the traditional CIS which exhibiting a special tail in noise histogram. The tail gradually disappears as the increase of TDI stages and finally exhibits a Gaussian distribution whose standard deviation is almost constant.Figure optionsDownload as PowerPoint slideHighlights
► A statistical model of RTS noise in TDI CIS is established.
► The relationship between RTS noise and the number of TDI stages is studied.
► The improvement of SNR is not in accord with the classical theory of Gaussian noise.
► There is a key TDI stages to get better RTS noise performance.