1×80 pixel SPAD-based flash LIDAR sensor with background rejection based on photon coincidence

We present a 1×80 pixel line sensor for direct time-of-flight measurement based on single-photon avalanche diodes fabricated in a high-voltage 0.35 pm CMOS process. An in-pixel time-to-digital-converter with a resolution of 312.5 ps determines the arrival time of the first-photon for each emitted laser pulse from a flash illumination source for all pixels in parallel. Distance determination is performed by collecting the time stamps over multiple pulses in a histogram and applying proper software algorithms. Ambient light suppression is achieved by detection of photon coincidences from four single SPADs in each pixel. By adjusting the time and depth of the coincidence detection a good result in varying ambient conditions is achieved.