Electronics of the ATLAS Liquid Argon calorimeter and its precision calibration

The Liquid Argon sampling calorimeter is a key detector component in the ATLAS experiment at the LHC, designed to provide precision measurements of electrons, photons, jets and missing transverse energy. In this note we present the detector readout electronics system and its precision calibration. The system has 182,468 channels with more than 16-bit dynamic range. The contribution to the relative energy resolution constant term due to the calibration uncertainty is below 0.25%. The radiation tolerant optical link between the detector front-end and the data acquisition back-end is also discussed.