The next section describes the IC EMC modeling with an ICEM model and a geometrical package description. Such models can be validated easily with scan measurements. The vertical cavity excitation sources, extracted from the scan data with (5.14) and (5.15), must match the EMC IC coupling model results from a simulation. The comparison has to be drawn with the IC on the same board under the same operational conditions. This means the same length of traces to the IC, the same PCB layer stack, the same power supply decoupling, the same running software, the same bus activity, and the same peripheral activity. In the case of deviations of scan measurement from simulation data, the simulation model can be adapted easily, because the comparison is made on individual excitation sources which allow an individual adjustment of source parameters in the model. For instance, an inaccuracy in the geometrical package description, which leads to a slight difference of the source position or the d/h factor may be corrected with the near field validation. Microcontrollers, but also smart power ICs, enable the peripheral and core activity to be controlled by software. Running different EMC validation software provides the opportunity for an individual check of the models for each IC module. Many devices provide a software slew rate control for the outputs. It is mandatory to use the same slew rates as in the final application for all EMC simulations and in each EMC validation software.
C. Poschalko: The Simulation of Emission from Printed Circuit Boards under a Metallic Cover
