Abstract
Abstract
The CMS tracking system will be completely replaced in order to operate in the extreme
conditions of the High Luminosity LHC. The new tracker will consist of two main subdetectors: the
Inner Tracker, containing pixel modules, and the Outer Tracker, consisting of strip and
macro-pixel modules. In the Inner Tracker, silicon sensors will be read out by the CMS Readout
Chip (CROC). The chip, built in 65 nm CMOS technology, is able to withstand high radiation doses
(500 Mrad) and hit rates (3 GHz/cm2 on the innermost tracking layer) during
operation. Moreover, it must handle a fine sensor granularity (2500 µm2
pixels) and operate at low detection thresholds (1000 e-). The Inner Tracker will
make use of the serial powering scheme to provide the ∼60 kW required by ∼4000
modular units. The Shunt-LDO (SLDO) regulator is the part of the CROC responsible for providing
the power by draining a constant current in time, independently of the chip power consumption.
Tests performed with Single Chip Cards (SCC) in serial configurations are reported in this paper.