A CMOS SPAD Sensor With a Multi-Event Folded Flash Time-to-Digital Converter for Ultra-Fast Optical Transient Capture

A digital silicon photomultiplier in 130-nm CMOS imaging technology implements time-correlated single photon counting at an order of magnitude beyond the conventional pile-up limit. The sensor comprises a $32 \times 32\,\,43$ % fill-factor single photon avalanche diode array with a multi-event folded-flash time-to-digital converter architecture operating at 10 GS/s. 264 bins $\times16$ bit histograms are generated and read out from the chip at a maximal 188 kHz enabling fast time resolved scanning or ultrafast low-light event capture. Full optical and electrical characterization results are presented.