Experimental characterization of the TOFPET2 ASIC

Abstract

We present the experimental characterization of the TOFPET2, a readout and digitization ASIC for radiation detectors using Silicon Photomultipliers. The circuit is designed in CMOS 110 nm technology, has 64 independent channels and is optimized for time-of-flight measurement in PET or other applications. The chip has quad-buffered TDCs and charge integration QDCs in each channel. The Coincidence Time Resolution (CTR) of 511 keV photon pairs from a 22Na point source measured with 2 × 2 × 3 mm3 LSO:Ce crystals co-doped with 0.2% Ca is 118 and 119 ps FWHM when using respectively the SiPMs NUVHD 40um from Fondazione Bruno Kessler (FBK) and the S14160-3050HS MPPC from Hamamatsu Photonics (HPK). The energy resolution obtained for the 511keV photopeak is 10.5 and 12% FWHM when using respectively the SiPMs PM3325-WB from KETEK and the QFBR-S4N44P164S from Broadcom Inc.