The Trigger Readout Electronics for the Phase-1 Upgrade of the ATLAS Liquid-Argon Calorimeters

The upgrade of the Large Hadron Collider, scheduled for 2019-2020, will increase the instantaneous luminosity by more than three, hence the ATLAS trigger rates. To cope with this increase, the trigger signals from the ATLAS Liquid Argon Calorimeter will be rearranged in 34000 so-called super cells to get a 5 to 10 times finer granularity. This will improve the background rejection performance through more precise energy measurements and the use of shower shape information to discriminate electrons, photons and hadronically decaying tau leptons from jets. The new system will process the super cell signal at 40 MHz and with 12 bit precision. The data will be transmitted at 5.12 Gb/s to the back-end system using a custom serializer and optical transmitter. To verify full functionality, a demonstrator set- up has been installed on the ATLAS detector and operated during the LHC Run 2. This document gives a status on hardware developments towards the final design readout system, including the performance of the newly developed ASICs. Their radiation tolerance, the performance of the prototype boards, results of the high-speed link test with the prototypes and the performance of the demonstrator with collision data are also reported.