A low noise digital readout system for scientific charge coupled devices

Abstract

Fully depleted thick CCDs have been designed for infrared astronomy, but their low read-out noise of the order of ≈ 2 e− and their considerable mass of ≈ 5.2 g, allows novel uses for them in low energy threshold particle detection applications, such as the CONNIE and DAMIC experiments. For both experiments, a reduction of the CCD read-out noise is will produce an increase in the detection efficiency. Few works have demonstrated that is possible reduce the noise applying digital processing techniques, and it is a field that must be explored. In this work the design of a CCD digital acquisition system will be presented. The impact of key parameters as quantization noise, front-end gain and ADC noise will be analyzed. A prototype of the front-end electronics was successfully tested with a CCD exposed to X-rays, achieving 2.3e− of readout noise.