CLARO-CMOS, an ASIC for single photon counting with Ma-PMTs, MCPs and SiPMs

An ASIC named CLARO-CMOS was designed for fast photon counting with MaPMTs, MCPs and SiPMs. The prototype was realized in a .35 μm CMOS technology and has four channels, each with a fast amplifier and a discriminator. The main features of the design are the high speed of operation and the low power dissipation, below 1 mW per channel. This paper focuses on the use of the CLARO for SiPM readout. The ASIC was tested with several SiPMs of various sizes, connected to the input of the chip both directly and through a coaxial cable about one meter long. In the latter case the ASIC is still fully functional although the speed of response is affected by the cable capacitance. The threshold could be set just above the single photoelectron level, and with 1 ×1 mm 2 SiPMs the discrete photoelectron peaks could be well resolved