Design and performance of the ABCD3TA ASIC for readout of silicon strip detectors in the ATLAS semiconductor tracker

Abstract

The ABCD3TA is a 128-channel ASIC with binary architecture for the readout of silicon strip particle detectors in the Semiconductor Tracker of the ATLAS experiment at the Large Hadron Collider (LHC). The chip comprises fast front-end and amplitude discriminator circuits using bipolar devices, a binary pipeline for first level trigger latency, a second level derandomising buffer and data compression circuitry based on CMOS devices. It has been designed and fabricated in a BiCMOS radiation resistant process. Extensive testing of the ABCD3TA chips assembled into detector modules show that the design meets the specifications and maintains the required performance after irradiation up to a total ionising dose of 10 Mrad and a 1-MeV neutron equivalent fluence of 2×1014 n/cm2, corresponding to 10 years of operation of the LHC at its design luminosity. Wafer screening and quality assurance procedures have been developed and implemented in large volume production to ensure that the chips assembled into modules meet the rigorous acceptance criteria

Searches for Natural Supersymmetry in Hadronic Final States with Heavy Flavor at ATLAS

“…The hit resolution in the transverse direction (r-) is 17 µm, while the longitudinal hit resolution (z in the barrel, r in the end caps) is 580 µm [25,89]. Like the pixel detector, the strips are read out with radiation-hard front-end chips for a total of 6.3 million read-out channels [94]. The radiation dose received by the innermost barrel layer of the SCT is estimated to be 7,600 Gy/year [25], which is significantly less than pixel detector radiation flux.…”

The ATLAS Inner Detector commissioning and calibration

“…1 Cut-away image of the ATLAS Inner Detector back-to-back with the first pair at a stereo angle of 40 mrad to provide space points. The strips are read out by radiationhard front-end readout chips [8], each chip reading out 128 channels; the total number of readout channels is ∼6.3 million. The hit information is binary: a hit is registered if the pulse height in a channel exceeds a preset threshold, normally corresponding to a charge of 1 fC.…”

ATLAS silicon microstrip tracker operation and performance

“…The barrel modules are identical [5], whereas the end-cap ones come in 4 different types [6]. All SCT modules are built of 2 pairs of silicon (p-in-n) microstrip sensors, glued back-toback at an angle of 40 mrad to provide 2D space-points, see The readout of the SCT modules is performed by six 128-channel ADCD3TA chips [7] on each side of the module, fabricated in the radiation hard technology DMILL. The data signals, processed by the chips are pre-amplified, shaped, discriminated (compared to a nominal threshold of 1 fC) and finally digitized; binary output is produced.…”