2 EMC Phenomena and EMC Testing

Unlike many other design issues (for instance, power calculations), there are no exact rules for EMC design saying, “Do it like this and it will work.” Instead, there are a lot of design suggestions saying, “Do it like this and it may work,” or “This is more likely to work, but at a higher cost.”

For most applications, it is not possible to prove EMC compliance without actual lab testing. Several new CAD packages include EMC simulations. These may be good design help, saving some extra trips to the test lab, but they cannot replace the final compliance test.

This chapter will give a short introduction to the most common EMC phenomena encountered in MCU system designs. To make it easier to understand the different phenomena, the phenomena and the tests used to emulate them are described together.