The Silicon Drift Detector readout scheme for the Inner Tracker System of the ALICE experiment

The Silicon Drift Detectors ( SDDs) provide, through the measurement of the drift time of the charge deposited Ly the particle which crosses the detec tor, information on the impact point and on the energy deposition. The fore seen readout scheme is based on a single chip implementation of art integra ted circuit that includes ion-noise amplification, fast analog storage and analog to digital conversion, thus avoiding the problems related to the ana log signal transmission. A multievent buffer that reduces the transmission bandwidth and a data compression/zero suppression unit complete the archite cture. In this paper the system components design is described, together with the results of the first prototypes.