Time performance of voltage-mode vs current-mode readouts for SiPM´s

A comparison among different architectures of front-end preamplifiers for SiPM detectors is useful when relevant performance in terms of timing accuracy is required in single photon detection applications. Many different solutions have been proposed in the past, which can be grouped into three main approaches: charge sensitive amplifiers, voltage-mode amplifiers and current-mode buffers. Here these architectures have been discussed and their limitations and advantages have been highlighted. The comparison has been carried out considering a simplified model of the detector and the classical expression of the time jitter. The influence of parasitic effects associated to the interconnections between the SiPM and the front-end electronics has also been analyzed and the corresponding limitations to the achievable timing performance of the different front-end styles have been considered, in order to find out more about the most suitable approach. To support the analysis, simulations of simple circuit implementations of the compared architectures have been carried out, under equal conditions. The results of the study show that the charge sensitive amplifier configuration results to be inefficient, due to bandwidth limitations, and that the best timing accuracy performance can be achieved by a current-mode approach, especially when the interconnection parasitics become relevant.