Recent Developments on the Silicon Drift Detector readout scheme for the ALICE Inner Tracking System

Recent developments of the Silicon Drift Detector (~SDD~) readout system for the ALICE experiment are presented. The foreseen readout scheme is based on 2 main units. The first unit consists of a low noise preamplifier, an analog memory which continuously samples the amplifier output, an A/D converter and a digital memory. When the trigger signal validates the analog data, the ADCs convert the samples into a digital form and store them into the digital memory. The second unit performs the zero suppression/data compression operations. In this paper the status of the design is presented, together with the test results of the A/D converter, the multi−event buffer and the compression unit prototype.