Characterization of Single-Photon Avalanche Diodes in a 0.5- $\mu \text{m}$ Standard CMOS Process—Part 2: Equivalent Circuit Model and Geiger Mode Readout

This paper features a model that allows the design and simulation of perimeter-gated single-photon avalanche diodes (SPADs). The model enables both Geiger mode and DC mode simulations. The model's key parameters were extracted from measured characteristics of a perimeter-gated SPAD fabricated in a 3-metal, 2-poly, single well CMOS process. This paper also features a survey of state-of-the-art SPAD models. Last, this paper describes the design and measured characteristics of a pixel that includes a perimeter-gated SPAD and a mixed-signal readout circuit.