Optical Detection: Correlated Double Sampling in 5T APS

This lecture discusses the design and operation of a 5T RPS pixel used for correlated double sampling (CDS). The instructor begins by explaining the components of the 5T RPS pixel, including the photodiode, reset transistor, floating diffusion, and transfer gate. The process of correlated double sampling is outlined, emphasizing the measurement of the reset level followed by the signal level, and the subtraction of these two signals to enhance image quality. The instructor illustrates how the reset and signal levels are stored in capacitors and how the information is transferred from the photodiode to the output diffusion. The lecture also covers the rolling shutter mechanism, detailing how each line of pixels is read sequentially while integrating light. The instructor explains the challenges of implementing a global shutter and the implications of using a rolling shutter in the context of correlated double sampling. Overall, the lecture provides a comprehensive overview of the electronic design and operational principles behind 5T APS cameras.