An Ultrafast Active Quenching Circuit for SPAD in CMOS 28nm FDSOI Technology

A very fast Active Quenching-Active Reset Circuit is proposed for the afterpulsing reduction in a Single Photon Avalanche Diode (SPAD). The proposed circuit is designed in a 28 nm CMOS FDSOI (Fully Depleted Silicon On Insulator) technology which takes benefit from the Body Biasing. By means of a very fast detection circuit, the avalanche is detected in just 27 ps. The fast detection results in a quenching time of less than 210 ps with a 46% reduction of the charge involved in the avalanche process. This reduction in the avalanche charge should strongly reduce the afterpulsing effect.