Circuit for high precision detection of the time of arrival of photons falling on single photon avalanche diodes

The invention concerns an output circuit for extracting the avalanche pulse produced by an avalanche photodiode for single photon detection (Single Photon Avalanche Diode, SPAD), which makes possible to detect and measure with the best possible precision the time of arrival of an incident photon on the surface of said SPAD. The circuit is built with a coupling network, connected to a terminal of said SPAD biased at high voltage and a comparator. Said network is designed so that the differentiation time constant (lambda), introduced by said block, is less than the total duration (Tqa) of the avalanche current pulse, but longer than the risetime (Tra) of said pulse. The circuit object of the invention has the virtue of being usable in all the circuit configurations for avalanche quenching in SPADs described in the technical and scientific literature.