Performance study of HGCROC-v2: the front-end electronics for the CMS High Granularity Calorimeter

Abstract

The High Granularity Calorimeter (HGCAL), presently being designed by the Compact Muon Solenoid collaboration (CMS) to replace the existing endcap calorimeters for the High Luminosity phase of the LHC, will feature unprecedented transverse and longitudinal readout and triggering segmentation for both electromagnetic and hadronic sections. The requirements for the front-end electronics are extremely challenging, including high dynamic range (0-10 pC), low noise (2000 electrons), highprecision timing information in order to mitigate the pileup effect (25 ps binning) and low power consumption (15 mW/channel). The front-end electronics will face a harsh radiation environment which will reach 200 Mrad at the end of life. It will work at a controlled temperature of 240 K. HGCROV-V2 is the second prototype of the front-end ASIC. It has 72 channels of the full analog chain: low noise and high gain preamplifier and shapers, and a 10-bit 40 MHz SAR-ADC, which provides the charge measurement over the linear range of the preamplifier. In the saturation range of the preamplifier, a discriminator and TDC provide the charge information from TOT (Time Over Threshold) over 200 ns dynamic range using 50 ps binning. A fast discriminator and TDC provide timing information to 25 ps accuracy. Both charge and timing information are kept in a DRAM memory waiting for a Level 1-trigger decision (L1A). At a bunch crossing rate of 40 MHz, compressed charge data are sent out to participate in the generation of the L1-trigger primitives. We report on the performances of the chip in terms of signal-to-noise ratio, charge and timing, as well as results from radiation qualification with total ionizing dose (TID).

Readout electronics for the CMS Phase II Endcap Calorimeter: system overview and prototyping experience

“…The frontend electronics system is designed around a set of ASICs. The HGCROC [3] is the frontend readout chip, which receives signals from the Si sensors and digitizes them, providing ADC, TOT (time over threshold), and TOA (time of arrival) information. There are also two frontend concentrator chips: the ECON-T for the trigger path, which concentrates trigger channel data via one of 4 trigger algorithms, and the ECON-D for the data acquisition (DAQ) path, which performs channel alignment and zero suppression after the accept signal is received from the Level-1 trigger.…”

Design and Simulated Performance of Calorimetry Systems for the ECCE Detector at the Electron Ion Collider

“…These SiPMs are most sensitive around wavelengths of 450 nm, thus the wave length shifting fibers have to be chosen accordingly to peak in a similar region. The first signal processing happens after the ECal part of the module within the 5 cm space currently assigned for the FEMC read-out, realized using CMS HGCROC chips mounted on custom PCBs [11], which can simultaneously process 72 channels. The signals are then transmitted via fiber optic cables to the end of the module for further processing.…”

The CMS High Granularity Calorimeter Scintillator/SiPM Tileboards

“…3 has 64 detector channels, the number of channels varies from 48 to 96 for the different board sizes. Main component for the read out of the SiPMs is the analogue / digital ASIC HGCROC for up to 72 detector channels [4]. In order to limit the supply currents to the tileboards, two step-down DC-DC converters bPOL12 [5] form the power input to the tileboards with 10V input voltage and the output voltages of 1.5V and 3.3V.…”