Front-end chip for Silicon Photomultiplier detectors with pico-second Time-of-Flight resolution

摘要

A mixed-mode readout Application Specific Integrated Circuit (STIC3) has been developed for high precision timing measurements with Silicon Photomultipliers (SiPM) for medical imaging and particle physics applications. The STiC3 is a 64-channel chip, with fully differential analog front-end for cross-talk and electronic noise immunity. The time and charge information from the SiPM signals are encrypted into two time stamps generated by integrated Time to Digital Converter (TDC) modules with 50 ps time binning. The TDC data is stored in an internal memory and transferred to a PC via a 160 MBit/s serial link using an 8/10 bit encoding. The chip provides an input bias tuning in a range of 0-900 mV to compensate the breakdown voltage variation of individual SiPMs. The TDC jitter together with the digital part is around 37 ps. A Coincidence Time Resolution (CTR) of 213.6 ps FWHM has been obtained with 3.1 × 3.1 × 15m~2 LYSO:Ce scintillator crystals and Hamamatsu SiPM matrices (S12643-050CN(X)). Characterization measurements with the chip and its integration into the external plate of the EndoTOFPET-US prototype are presented.