Development of new readout electronics for the ATLAS LAr Calorimeter at the sLHC

The readout of the ATLAS Liquid Argon (LAr) calorimeter is a complex multi-channel system to amplify, shape, digitize and process signals of the detector cells. The current on-detector electronics is not designed to sustain the ten times higher radiation levels expected at sLHC in the years beyond 2019/2020, and will be replaced by new electronics with a completely different readout scheme. The future on-detector electronics is planned to send out all data continuously at each bunch crossing, as opposed to the current system which only transfers data at a trigger-accept signal. Multiple high-speed and radiation-resistant optical links will transmit 100 Gb/s per front-end board. The off-detector processing units will not only process the data in real-time and provide digital data buffering, but will also implement trigger algorithms. An overview about the various components necessary to develop such a complex system is given. The current R&D activities and architectural studies of the LAr Calorimeter group are presented, in particular the on-going design of the mixed-signal and radiation hard front-end ASICs, the Silicon-on-Saphire based optical-link, the high-speed off-detector FPGA based processing units, and the power distribution scheme