A custom front-end ASIC for the readout and timing of 64 SiPM photosensors

A new class of instruments – based on Silicon PhotoMultiplier (SiPM) photosensors – are currently under development for the next generation of Astroparticle Physics experiments in future space missions. A custom front-end ASIC (Application Specific Integrated Circuit) for the readout of 64 SiPM sensors was specified in collaboration with GM-IDEAS (Norway) that designed and manufactured the ASIC. Our group developed a custom readout board equipped with a 16 bit ADC for the digitization of both pulse height and time information. A time stamp, generated by the ASIC in correspondence of the threshold crossing time, is digitized and recorded for each channel. This allows to define a narrow time window around the physics event that reduces significantly the background due to the SiPM dark count rate. In this paper, we report on the preliminary test results obtained with the readout board prototype.