A combined time and frequency domain characterization method for modeling of overvoltage protection elements

Abstract

Nonlinear voltage sensitive protection elements, e.g. Multi-Layer Varistor (MLV) or Transient Voltage Suppressor (TVS) are useful to protect IC pins from ESD on System Level. Such elements might exhibit a significant voltage overshoot for fast transients. This work describes a combined time and frequency domain characterization method and its application to an MLV. Impedance measurements with VNA at different DC-bias points are used for model identification and parameterization. The static nonlinear IV-behavior of nonlinear model part at higher voltages and currents is extrapolated with a TLP IV-curve. The model is successfully validated with ESD pulses in time domain. The transient behavior including the occurring voltage overshoot can be reproduced with high accuracy.