Lab-On-A-Chip (LOC) devices that utilize lightbased detection principles offer advantages compared with their electronic counterparts, such as higher sensitivity and not necessarily needing markers, simplifying their use, and reducing reagent consumption. Recently, the development of Si-based light emitters compatible with standard CMOS manufacturing processes has overcome one of the main obstacles in creating fully integrated electrophotonic systems on the same substrate. This groundbreaking achievement means the possibility of integrating photonic and driving circuitry in the same chip. However, due to its extreme novelty and specific electronic requirements, new design solutions must be tailored to further aid fulfilling the promise of a fully integrated electrophotonic system. The lack of existing circuit design models and tools hinders the advancement of this technology. To aid further in designing these systems, this article presents the development of a Verilog-A macromodel for an electrophotonic circuit composed of a Light Emitting Capacitor (LEC), a waveguide, and a sensor. The system was simulated in the Cadence Virtuoso environment, and a use case exhibits the system simulation including a CMOS circuit for emitter excitation and sensor reading.