Fully Integrated Active Quenching Circuit Driving Custom-Technology SPADs With 6.2-ns Dead Time

The minimization of the dead time necessary for the operation of a single-photon avalanche diode (SPAD) plays a crucial role in many demanding single-photon applications. Among these, it is worth mentioning the implementation of airborne light detection and ranging systems exploited to scan the terrain topography through semiporous obscurations. In this letter, we present the development and the experimental characterization of a fully integrated active quenching circuit able to drive custom-technology SPADs with a dead time as low as 6.2 ns, corresponding to a maximum photon count rate of more than 160 Mcps. Thanks to the use of a high-voltage CMOS fabrication technology, the circuit is able to operate also SPADs that require an excess bias of few tens of Volts, like the recently developed red-enhanced SPAD up to a maximum photon count rate of 100 Mcps.