REDESIGN OF THE ATLAS TILE CALORIMETER READOUT LINK AND CONTROL BOARD FOR THE HIGH LUMINOSITY LHC ERA

The R\&D for the new on-detector electronics for the Phase-II ATLAS upgrade for the High Luminosity Large Hadron Collider (HL-LHC) has motivated progressive redesigns of the ATLAS Tile Calorimeter (TileCal) Daughterboard (DB). The DB is the readout link and control board interface to the off-detector electronics of TileCal. The DB receives configuration commands and LHC timing via two CERN radiation-hard GBTx ASICs and two redundant 4.8 Gbps downlinks. Two Ultrascale+ FPGAs propagate the control to the front-end. Simultaneously, the FPGAs send continuous high-speed readout of digitized Photomultiplier Tube (PMT) samples through four 9.6 Gbps uplinks. We present a DB redesign that further improves the timing scheme, and enhances the radiation tolerance of the board by mitigating SEL induced errors and implementing a more robust power-up and current monitoring scheme. The design minimizes points of failure and reduces sensitivity to SEUs and radiation damage by employing a double-redundant scheme, using Triple Mode Redundancy (TMR) and Xilinx Soft Error Mitigation (SEM) in the FPGAs, adopting Cyclic Redundancy Check (CRC) error verification in the uplinks and Forward Error Correction (FEC) in the downlinks.