Prototype Module Construction for the High Luminosity Upgrade of the CMS Pixel Detector

With the planned upgrades of the LHC towards high luminosity operation, the entire CMS silicon tracker will be replaced in order to cope with the resulting elevated pileup and radiation levels. To fulfill these requirements for the CMS pixel detector, a new readout chip was developed by the RD53 collaboration in 65 nm CMOS technology, featuring a higher readout bandwidth along with increased granularity and radiation tolerance. These chips are operated at high currents rendering the classical parallel powering of individual devices inefficient. A serial powering concept was therefore developed where the input current is shared by a chain of devices. This reduces considerably the power loss in the detector services thus keeping the requirements for powering and cooling at acceptable levels. Based on the availability of the Shunt-LDO, a voltage regulator compatible with the serial powering scheme, on the RD53 chip, a novel module concept was developed. This paper presents the module design and implementation based on the prototype RD53A devices which were evaluated in single operation and as part of a serial powering scheme.