Investigation of a Readout Circuit Design that Reduces Effective Capacitance of Large Area SiPMs

In order to provide a large photo-sensitive area, silicon photomultipliers (SiPMs) comprise thousands of Geiger-mode avalanche photodiodes (GM-APDs) connected in parallel. This results in a large device capacitance that causes R-C shaping of output signals, elongating signal rise time and reducing signal-to-noise ratio (SNR). One aspect of SiPMs that this affects is achievable single photon timing resolution (SPTR), where the increased signal rise time and reduced amplitude degrades timing jitter, according to the relationship in Equation 1.