A Behavioral Model for High-Speed 4:1 Analog Multiplexers, utilizing Stochastic Modelfitting

High-Speed digital-to-analog converters (DACs) are essential components in optical transmitters for global communication networks. As the demand for increased analog bandwidth grows, the commonly used, cost-effective CMOS technology is approaching its limitations. A promising solution is the interleaving of multiple DAC outputs through the nonlinear operation of an analog multiplexer (AMUX) in silicon-germanium technology. In this work, we present a behavioral model for 4:1 AMUX ICs, which reduces run times for system-level simulations by several orders of magnitude compared to layout-level IC simulations. We fit the model parameters using reference data from a 4:1 AMUX layout simulation while utilizing a stochastic algorithm to autonomously search the parameter space. The results show a close match of the reference data with the model output with low overfitting tendency, but also considerable variability in parameter influence on model accuracy.