Multi Correlated Double Sampling with exponential reset

Multiple Correlated Double Sampling is often used to readout detectors with known periodic signal arrival time. New high rate applications such as X-ray Evolving Universe Spectroscopy mission demand high energy resolution which requires the filter properties to be optimized under the experimental constraints. Here we present an analysis and interpretation of the filter performance of a Multi Correlated Double Sampling system in terms of the signal-to-noise ratio as a function of the number of samples and the bandwidth of the sampling device including an exponential reset. In a real device, a signal arriving before the measurement cycle has an effect, on the measurement itself, which depends on the time difference between the signal arrival time and beginning of the actual measurement cycle. The effect of the reset on the sampling window will be approximated by an exponentially decaying time function. The introduction of such a reset is necessary to describe correctly a Multi Correlated Double Sampling system with the weighting function concept. Once the signal and the noise at the input of the filter are known, the present work provides the designer with a guideline to derive the filter parameters that optimize the signal-to-noise-ratio according to specific application constraints.