The ATLAS pixel front-end readout chips

Large advances have been made over the last three years in the development of the front-end readout electronics for the ATLAS (Atlas Tech. Proposal, The ATLAS Collaboration CERN/LHCC/94-43) Pixel (Inner Detector TDR, The ATLAS Collaboration CERN/LHCC/ 97-17) Tracker. I describe here the Pixel Demonstrator Programme, the initial phase of which involved the production of two realistic ATLAS prototype front-end readout chips using non-radiation tolerent processes (AMS BiCMOS and HP CMOS, both 0.8 μm). In the next phase of the programme, a single front-end design was fabricated in a radiation-hard technology (0.8 μm DMILL).Subsequent evaluations of this chip are also discussed herein.