Modeling the static and dynamic behavior of multi-layer varistors in the threshold voltage region depending on the DC operating point

In this work, a novel approach to the modeling of ESD protection elements multi-layer varistors (MLV) is presented. Based on measurements of the static I-V-characteristics, an approach similar to the EKV model is used instead of the known ideal I-V-characteristics in the threshold voltage region. Additionally, an equivalent circuit for the representation of the impedance frequency response (especially its low- and mid-frequency behavior) is derived from impedance measurements depending on the varistor´s DC operating point. The established model includes frequency depending resistances known from skin effect modeling.