Prototyping Serial Powering for the ATLAS ITk Pixel Detector

The high luminosity upgrade for the LHC at CERN requires a complete overhaul of the current inner detectors of ATLAS and CMS. A serial powering scheme has been chosen to cope with the constraints of the new pixel detectors. A prototype stave consisting of up to 8 quad modules, based on the new readout chips developed by the RD53 collaboration in 65 nm CMOS technology, RD53A, and ITkPixV1, has been set up in Bonn. This contribution covers the results obtained with RD53A modules and presents. first measurements with a full ITkPixV1.1 serial powering chain.