Design of the ATLAS IBL Readout System

An Insertable B-Layer is planned for the upgrade of the ATLAS detector and will add a fourth and innermost pixel layer to the existing Pixel Detector. 12 million pixels attached to new FE-I4 readout ASICs will require new off-detector electronics which is currently realized with two VME-based boards: a Back Of Crate module implementing optical I/O functionality and a Readout Driver module for data processing. This paper illustrates the new readout chain, focusing on the design of the new Readout Driver Card, which, with a fourfold integration with respect to the previous design, builds up the detector data, controls the calibration procedures and interacts via Gigabit links with a novel calibration farm. Future prospects and back compatibility to the existing system are also addressed