Testing and characterisation of the prototype readout chip for the High-Luminosity LHC upgrade of the CMS Inner Tracker

Abstract This contribution describes the characterisation and validation campaign of the prototype of the CMS Readout Chip (CROC), a 65 nm CMOS pixel readout ASIC for the CMS Inner Tracker upgrade for High Luminosity LHC. This validation campaign includes tests with single-chip and multi-chip modules, irradiation campaigns, test beams and wafer-level tests. The main results obtained in the testing of the CROC prototype will be outlined. Key improvements and fixes that have been implemented in the final version of the chip before the October 2023 submission will be described.