HGCROC3: the front-end readout ASIC for the CMS High Granularity Calorimeter

Abstract For the CMS High Granularity Calorimeter (CE), final version of 72-channel front-end ASIC (HGCROC3) was submitted in December 2020. HGCROC3 includes low-noise/high-gain preamplifiers/shapers and a 10-bit 40 MHz successive approximation ADC (SAR-ADC) that provide charge measurement over linear range preamplifier. In saturation range, discriminator time-to-digital converter (TDC) information from time threshold (ToT; 200 ns dynamic 50 ps binning). A fast another TDC timing to 25 accuracy. The chip embeds all necessary ancillary services: bandgap circuit, PLL, DACs. We present experimental results on latest received April 2021.