Studies of the low voltage power supply for a highly segmented fast detector

The experiments at the Large Hadron Collider are upgrading their detectors for the coming High Luminosity run. Powering the on board electronics of the highly segmented tracking detectors is a challenge because of the stringent requirements on location, space constraint, fine segmentation, radiation and magnetic field tolerance, thermal loss, etc. Similar issues will be relevant for the future colliding beam experiments, also. This paper reports early studies of the Low Voltage Power Supply for the upgrade of the Outer Tracker detector of the Compact Muon Solenoid experiment. The proposed power chain uses point of load DC-DC converters. The studies, with simulations and experimental measurements, have identified a number of critical issues related to the voltages and currents of the DC-DC converters under different operating conditions. A few constraints on the design of such a system have been identified and in some cases remedial measures to circumvent such constraints have been suggested.