SPACIROC3: 100 MHz photon counting ASIC for EUSO-SPB

Abstract SPACIROC (Spatial Photomultiplier Array Counting and Integrating ReadOut Chip) is the front-end ASIC dedicated to readout 64-channel Multi-Anode Photo-Multiplier Tube (MAPMT). In 2017, it was used for the Extreme Universe Space Observatory on a super pressure balloon (EUSO-SPB) instrument which is a pathfinder for space cosmic ray fluorescence detectors. EUSO-SPB was launched by NASA from Wanaka, NZ on the 24th of April 2017. The flight has been a success both on technological and scientific point of views. The instrument was equipped with a set of lenses to focus the UV photons on the Photo Detector Module (PDM) which was controlled by the Data Processing system. The photo detection focal surface is made of 36 MAPMTs with high voltage sub-system (HVPS). The MAPMT signals are transmitted to SPACIROC3 ASIC which performs single photon counting with low power consumption ( 1  mW/ch). This proceeding presents in detail the performances of the SPACIROC3 ASIC.