A 15 × 15 single photon avalanche diode sensor featuring breakdown pixels extraction architecture for efficient data readout

Abstract

This paper proposes a breakdown pixels extraction architecture for single photon avalanche diode (SPAD) based faint light detection systems. The proposed extraction circuit detects the breakdown pixels and only their addresses are readout. Therefore, under the faint light environment, this SPAD-based sensor significantly improves the data readout efficiency. In addition, since the readout sequence is 4× faster than that of the conventional architecture in the dark condition, the proposed system does not need an independent on-chip event detection circuit that consumes additional area and power. A test-of-concept chip with a 15 × 15 SPAD pixels array was fabricated in a 0.18 µm 1P5M standard CMOS process and pinhole diffraction patterns were successfully captured thanks to the high sensitivity of the SPAD sensor. Under the faint light condition, a high-speed readout is verified by measurement and the robustness of the proposed architecture is successfully demonstrated.