An ASIC for Delta Sigma Digitization of Technical CCD Video

with permission of SPIE. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, dupli- cation of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited. Delta Sigma digitizers generally have excellent linearity, precision and noise rejection. They are especially well suited for implementation as integrated circuits. However, they are rarely used for time bounded signals like CCD pixels. We are developing a CCD video digitizer chip incorporating a novel variant of the Delta Sigma architecture that is especially well suited for this application. This architecture allows us to incorporate video filtering and correlated double sampling into the digitizer itself, eliminating the complex analog video processing usually needed before digitization. We will present details of a multichannel ASIC design that will achieve spectroscopic precision and linearity while using much less energy than previous CCD digitizers for technical applications such as imaging X-ray spectroscopy. The low conversion energy requirement together with the ability to integrate many channels will enable us to construct fast CCD systems that require no cooling and can handle a much wider range of X-ray intensity than existing X-ray CCD systems