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 mu m 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 mu m(2). Such outstanding advantages suggest that the proposed AQRC is very suitable for the miniaturized and high-speed SPAD-array detectors.