Approximate Solutions for Nonlinear Diode–RC Circuits: Short Communication Using Lambert W and g ‐Function Approaches

ABSTRACT This short communication presents approximate solutions for a nonlinear diode circuit followed by an RC shunt filter. The diode's exponential current–voltage characteristic introduces strong nonlinearity, making the analysis challenging. By applying the Lambert W function, closed‐form approximations of the circuit voltages and currents are derived. These expressions are further enhanced through a g ‐function‐based approach to overcome the numerical limitations of the Lambert W evaluation. The proposed model is validated through MATLAB/SIMSCAPE and PSIM simulations, and further assessed using high‐fidelity software simulations within the Typhoon HIL environment, demonstrating excellent consistency with the reference results. Furthermore, the impact of different diode modeling approaches on the output voltage waveforms is systematically analyzed, revealing a pronounced influence on both amplitude and transient behavior. The presented method thus offers an accurate, computationally efficient, and experimentally confirmed analytical tool for the modeling of nonlinear diode–RC circuits.