A Compact High-Speed Active Quenching and Recharging Circuit for SPAD Detectors

A compact high-speed active quenching and recharging circuit (AQRC) is proposed for single-photon avalanche diode (SPAD) detectors fabricated in standard 0.18 μm CMOS technology. A novel sensing and quenching scheme is employed to speed up the process of avalanche detection, enabling a low afterpulsing probability and a high photon-counting rate. The simulation and experimental results indicate that the sensing and quenching time is reduced down to 0.7 ns and the maximum photon-counting rate is close to 200 Mcps (counts per second), meanwhile the afterpulsing probability as low as 0.75% is obtained. Due to the compact configuration, the area occupation of the AQRC is only 306 μm 2 . Such outstanding advantages suggest that the proposed AQRC is very suitable for the miniaturized and high-speed SPAD-array detectors.