11 Oct/22
09:00 - 10:00 (Europe/Zurich)

LAr Phase-2 HL-LHC Upgrade: The COLUTA ADC


13/2-005 at CERN



The upgrade to the high-luminosity LHC (HL-LHC) will yield approximately 200 inelastic proton-proton collisions per beam crossing at energies of up to 14 TeV. The ATLAS Liquid Argon (LAr) calorimeter is expected to gather 4,000 fb−1 of collision data during the operational lifetime of the HL-LHC to support the pursuit of physics inquiries into the Standard Model.  The higher luminosity places increasingly stringent radiation-tolerance requirements and the need for seamless integration of on-detector readout electronics, in addition to better quantization performance to yield better physics results.  This talk discusses the evolution of the LAr readout with a particular emphasis on the design of a full-custom analog-to-digital converter (ADC) for the 182,468 channels in the ATLAS LAr calorimeter as part of the HL-LHC phase-2 upgrade. 

Each of the 8 channels in the prototype 65 nm CMOS ADC with 15-bit resolution and >68 dB signal-to-noise-and-distortion ratio (SNDR), or equivalently >11 effective number of bits (ENOB), consists of a Multiplying-DAC (MDAC) and a successive-approximation (SAR) ADC. A digital data processing unit (DDPU) calibrates and serially transmits the quantized data. Initial lab characterization of 18 chips shows a minimum SNDR of 69.5 dB at full-scale at about 5 MHz and a maximum power consumption of 1.17 W; differential non-linearity (DNL) measurements show no missing codes. Additional validation of the ADC is ongoing before approximately 70k chips can be mass-produced for the upgrade.  The transistor-level design, system-level architecture, as well as the foreground calibration principle will be discussed in this talk.

Participating Institutions:

  • Columbia University, Nevis Labs
  • Columbia University, Electrical Engineering Department
  • University of Texas at Austin, Physics Department
  • University of Texas at Austin, Electrical and Computer Engineering Department

Zoom details are also in the invitation email.

Make sure you have the latest Zoom client app to be able to connect https://cern.zoom.us/ -> Download client