Correlated noise in pixel detectors with analogue readout

A calculation of the spatial resolution achievable, in both dimensions, in silicon pixel detectors equipped with analogue VLSI readout cells, exploiting capacitive cross-talk effects among neighbouring active elements, has been performed. Noise correlation among close pixels has been considered and the total correlated noise has been evaluated. The very good signal/noise ratio allows to obtain very good 2-dimensional resolutions even with macropixels with hundreds of μm sides. The spatial accuracy achievable with a “chessboard-like” readout scheme to limit the number of analogue channels has also been considered. It turns out that, this being the case, it is possible to reach good spatial resolutions by exploiting capacitive coupling among neighbouring diodes to reduce the total number of analogue readout channels.