Low-power compact tunable quenching configuration for minimizing afterpulsing in single-photon avalanche diodes

This paper unveils two efficient free running (FR) quenching circuits with the aim of reducing quenching time (QT) to minimize avalanche charge. Likewise, one circuit is compactly designed with low power consumption, suitable for single-photon avalanche diode ( SPAD) with hold-off time below 10 ns. In second circuit, tunable hold-off and reset-time are provided within a wide range without decreasing QT, which are desirable in many applications. Proper operation and circuit uncertainty is assessed by Monte Carlo analysis in a standard 90-nm complementary metal-oxide semiconductor (CMOS) technology. In a bid to do a comparison between previously reported circuits and the proposed circuits, they are simulated with same SPAD model and parameters and results corroborate the proposed circuits guarantee active quenching time (AQT) of below 1 ns. Proposed circuits with current and area consumption of 0.74 μA, 32 μm² for 7-ns dead time and 16.2 μA, 93 μm² for 21-ns dead time are more efficient in terms of QT, area, and power consumption in comparison with other works.