Impact of Diode Variability on EM Immunity: Analysis with Measurement and Simulation

Multisourcing of diodes must be considered during design activities, especially for EMC. For immunity aspects, several characteristics are relevant to compare the different sources. This paper proposes a method to obtain the critical parameters of a diode and to analyze their impact on diode immunity behavior. A simple DPI setup is used to model an immunity test. Impedance, junction capacitance and I-V characteristic of the diode are measured to create a model of the diode and build the DPI test in circuit simulation. Simulation results show the need for an accurate model of the junction capacitance. Finally, the components tolerance and measurement accuracy are integrated in the simulation to estimate the possible deviation in the DPI setup. Those criteria are considered for immunity aspect only. For emission aspect, additional characteristic needs to be analyzed.