Pixel design for time-of-flight range detector with time-to-digital converter

A novel pixel structure for the readout of SPAD range detector has been proposed in this paper, which aimed at 3D ranging applications by means of the direct time-of-flight (D-TOF) detection. The proposed pixel is consist of a single photon avalanche diode (SPAD), quenching-recharging circuit and 10 bit time-to-digital converter which provides a minimum time resolution of 141ps. Coarse-fine architecture has been used to provide both wide dynamic range and high time resolution. The chip has been fabricated in 0.18 µm GSMC 1P4M imaging process. The resulting pixel has a pitch of 100µm.