| EMC for ICs > Models for EMC Simulation | |
The complete flow for comparing measurements to simulations is given in this figure. Concerning simulation, our task is to define a model of the board including the IC, the package, the measurement probe and the test board. Each part requires some specific model. The measurement is done using a frequency analyzer of a high bandwidth oscilloscope. The fast Fourier transform and the appropriate post-processing transforms the measurement data into a plot of the dBµV versus frequency.
Here is a concrete example of simulation compared with measurements, using the conducted 1ohm probe. The measurement is provided by a high quality frequency analyzer, and the model is given by a SPICE analog simulation in time domain, converted in the appropriate units (dBµV vs frequency) by fast Fourier transform.
The same model applies well in the prediction of the spectrum emitted in the TEM cell by integrated circuits. The core model is then connected to the TEM cell using two elements: a capacitor Cdie_septum and a coupling between inductors.
This is an example of comparison between measurements of a 16-bit micro-controller emission in TEM cell and the simulation based on the ICEM model, coupled to the TEM cell by the capacitor and inductor coupling.
| EMC for ICs > Models for EMC Simulation > Correlation Measurements/Simulation | |