A digital CDS technique and the performance testing

TL;DR

This paper introduces a digital correlated double sampling (CDS) technique for CCDs that reduces readout noise by digitizing signals directly, improving energy resolution without traditional analog noise sources.

Contribution

It presents a novel digital CDS method that bypasses analog components, achieving lower noise and better performance in CCD readout.

Findings

Achieved a readout noise of 3.3 electrons.

Attained an energy resolution of 121 eV at 5.9 keV.

Demonstrated effective noise reduction compared to conventional methods.

Abstract

Readout noise is a critical parameter for characterizing the performance of charge-coupled devices (CCDs), which can be greatly reduced by the correlated double sampling (CDS) circuit. However, conventional CDS circuit inevitably introduces new noises since it consists of several active analog components such as operational amplifiers. This paper proposes a digital CDS circuit technique, which transforms the pre-amplified CCD signal into a train of digital presentations by a high-speed data acquisition card directly without the noisy CDS circuit first, then implement the digital CDS algorithm through numerical method. The readout noise of 3.3 e$^{-}$ and the energy resolution of 121 eV@5.9keV can be achieved via the digital CDS technique.