rPOL2V5: a compact radiation-hard resonant switched-capacitor DC-DC converter for the CMS HGCAL

Abstract

A radiation-tolerant resonant switched-capacitor DC-DC converter (rPOL2V5) has been developed to supply the front-end analog and digital circuits for the detectors used in the LHC High Luminosity upgrades. It has been of particular interest to the CMS High-Granularity Calorimeter (HGCAL) community due to its lower volume compared to existing radiation-hard buck converters. rPOL2V5 is based on an ASIC developed using 130 nm CMOS technology. It is powered by a 2.5 V input and it can supply a maximum current from 2 A to 5 A, depending on the output voltage value, which can range from 1 V to 1.5 V. This work presents the strategies adopted at the ASIC and PCB level to bring the converter to maturity, and its electrical and radiation characterisation results.