Implementation of the ASDBLR straw tube readout ASIC in DMILL technology

The ASDBLR ASIC provides eight channels of low noise, low power, high rate on-detector readout suitable for the ATLAS Transition Radiation Tracker (TRT) at the LHC. The TRT's unprecedented wire chamber readout requirements of a maximum hit rate per wire of 20MHz and double pulse resolution of similar to 25ns with position resolution of better than 150mum in a high radiation environment have been addressed in the design of the ASDBLR. A carefully tuned ion tail cancellation stage followed by an output sensing baseline restorer implemented in differential structures provides robust signal processing combination compatible with the realities of ASIC design. Two comparators track the output of the signal processing stage to provide Tracking information from charged particles and evidence of higher energy Transition Radiation (TR) photons; their outputs are summed as current steps to form a differential ternary output. The ten year total dose requirement for neutrons of 10**1**4 n/cm**2 and 1.5 MRad of ionizing radiation led to the implementation of this design in the radiation hardened DMILL process. 4 Refs.