Speaker
Description
In this contribution, we present ALDO2, a multi-function, adjustable, low dropout linear regulator designed in onsemi I3T80 0.35 $\mu$m HV CMOS technology for use in HEP detectors that adopt SiPMs/MPPCs.
The chip features four independent regulators, two low voltage channels (max 3.3 V) used to filter and stabilize the power supply of front-end chips, one with 0.6 A output and one with 20 mA output, and two HV channels (max 70 V), specifically designed to provide the bias voltage to arrays of SiPMs up to a current of 45 mA per channel.
Each regulator can be independently shut down and is protected for over-currents and over-temperature.
The HV regulators also implement a circuit to monitor the bias current of the SiPM arrays, allowing to perform I-V curves and thus to fine-tune the working point of the SiPM arrays during the detector lifetime.
The chip adopts radiation hardening techniques and has been fully qualified up to a TID of 20 Mrad, a 1-MeV-equivalent neutron fluence of $10^{15}$ cm$^{-2}$, and with heavy ions up to 40 MeV cm$^2$ mg$^{-1}$ LET and $10^{10}$ cm$^{-2}$ cumulative fluence. The chip will be installed in two CMS detectors in the HL-LHC phase, the Barrel Timing Detector (BTL) and the High Granularity Calorimeter (HGCAL).
