Recent Results from the First lpGBT-based Prototype of the End-of-Substructure Card for the ATLAS ITk Strip Detector

The main building blocks of the ATLAS Inner Tracker (ITk) Strip Detector, to be installed for the High-Luminosity Upgrade of the Large Hadron Collider (HL-LHC), are modules that host sensors and front-end ASICs. Carbon-fibre substructures provide mechanical support to up to 14 modules per side. An End-of-Substructure (EoS) card on each substructure side connects up to 28 differential data lines at 640 Mbit/s from the module to low-powered GigaBit Transceivers (lpGBT) ASICs for data serialisation and uses 10 GBit/s optical links to transmit signals to the off-detector systems via the Versatile Link PLUS (VL+) transceiver module, VTRx+. Prototype EoS cards have been designed and extensively tested using lpGBT and VTRx+ prototypes. The status of the electronics design and recent results of tests of electrical and data processing performance based on these prototypes are presented.