A Spatially Distributed Single Photon Avalanche Diode Verilog-A Compact Model

Single photon avalanche diodes (SPADs) are crucial for Industry 4.0 advancements, especially in the design of LIght Detection And Ranging (LIDAR) sensors. A compact model is needed to accurately describe their transient behavior. This article presents a lumped model approach that divides the device into different regions. The model accurately emulates the behavior of reach-through SPAD photodiodes by dividing them into high electric field multiplication and low electric field absorption regions. The absorption region can be further subdivided to create multiple possible photon impact points, resulting in precise jitter modeling. This approach enables adaptable and unified SPAD modeling for different avalanche diode architectures. Experimental data confirm the accuracy of the model, and the characterization technique developed highlights the stochastic nature of the device.