A 16 channel ASIC for silicon drift chamber read out

A prototype Application Specific Integrated Circuit (ASIC) to read out Si drift detector signals has been realized and characterized. The device is based on the ICARUS ASIC that is currently employed into the PICsIT detector on board the INTEGRAL satellite. This new ASIC includes 8/spl times/2 processing chains each consisting of a shaping amplifier, peak detector & hold stage, amplitude discriminator (trigger), trigger logic commanding with signal I/F, selectable threshold level for the trigger generation, address attribution, On/Off of the channels via a bit register (KILL-PIX function) and I/O external flags management. The charge preamplifiers collecting the signal from the detectors are externally mounted in order to support a wide range of uses. The first 8 channels exhibit a short integration time in the shaping stage and are tailored for the use of the SDC as a direct radiation detector while the remaining 8 channels, with a larger integration time, are tailored to the use of the SDC coupled to a crystal scintillator. The ASIC functional behavior is described and its performances are summarized and discussed.