RDS and IRDS filters for high-speed CCD video sensors

In this brief, we present two filters called “reflection delayed noise suppression” (RDS) and “integration reflection delayed noise suppression” (IRDS) which are useful to increase dynamics of video charge-coupled device (CCD) cameras. The RDS is a band-pass filter built with a parallel short-circuited line. It significantly lowers the most important noise, called reset noise. Unfortunately, this signal processing unit increases the contribution of thermal fluctuations by at least 3 dB. To overcome this disadvantage, a reset low-pass filter can be added to the RDS cell, which leads to the IRDS method. For both methods, we will describe the principle and compare their effects in a theoretical way, and by experimentation on sensing-node amplifier and reset noise in the CCD sensor