Avalanche current read-out circuit for low jitter parallel photon timing

Electron Lett. 2013 Aug 1;49(16):1017-1018. doi: 10.1049/el.2013.1879.

Abstract

We propose a novel circuit for single photon avalanche diode (SPAD) current read-out, for photon timing applications. The circuit consists of a single transistor trans-impedance amplifier with a GHz bandwidth: the feedback loop fixes the SPAD anode voltage and allows us to obtain a high time resolution with a very high equivalent current threshold (almost 700 μA). The trans-impedance stage is followed by a low pass filter that reduces the crosstalk of other on-chip detectors and makes the designed structure suitable for multi-detector systems. The discrete components prototype presented in this letter achieves a state-of-art resolution of 34.4 ps FWHM, presents negligible crosstalk between the different pixels and opens the way for the development of an integrated structure with a large number of channels.