CMOS Cameras: Detection and Electronics Overview

This lecture covers the principles and technologies behind CMOS cameras, focusing on detection and electronics. It begins with an introduction to the four-transistor (4T) active pixel sensor (APS) architecture, explaining its advantages over the three-transistor (3T) design, particularly in terms of correlated double sampling (CDS) and global shutter capabilities. The instructor discusses the structure of the photodiode, including the pinned photodiode (PPD) and its benefits, such as low dark current and reduced reset noise. The lecture also highlights the importance of output diffusion and the design considerations for achieving high sensitivity and low noise. The differences between rolling shutter and global shutter mechanisms are explained, emphasizing the advantages of global shutter for capturing fast-moving images without distortion. The session concludes with a summary of the key features of 4T APS technology and the challenges that remain in integrating CDS and global shutter functionalities. Overall, this lecture provides a comprehensive understanding of the electronic components and operational principles of modern CMOS cameras.