This article describes an improvement in the noise reduction performance of a column correlated multiple sampling (CMS) readout circuit using interleaved pixel source follower for high-resolution and high-framerate CMOS image sensors (CISs). In this architecture, the timeinterleaved operation of the two pixel source followers reduces the restrictions imposed by the settling time of the pixel source followers and extends the time for multiple sampling. The noise analysis indicates that this method has an advantage of enhanced noise reduction not only for thermal noise but also for 1/f noise when a high-speed readout operation is required. The measurement of the noise performance of the 8K image sensor using the CMS with the interleaved pixel source follower method exhibits a low input-referred noise of 3.2 e − at 8K 120 frames per second, while 4.6 e − with the conventional single-source follower readout method. The measurement results match reasonably well with the analysis presented in this article, demonstrating the effectiveness of the interleaved pixel source follower method for high-resolution and high-framerate CISs.Index Terms-8K, CMOS image sensor (CIS), correlated multiple sampling (CMS), high resolution, noise reduction.
I. INTRODUCTIONT HE recent trends in video applications have tended toward increasing spatial resolutions, such as 4K, 8K, and high framerates. The video parameters of an ultrahighdefinition television (UHDTV) are standardized in recommendations ITU-R BT.