Design

Every EMI (electromagnetic interference) problem ultimately starts or ends at an electronic circuit. And since electronic components are the building blocks of circuits, it only makes sense to pay attention to the EMI impact of those individual components.

Probably the most important thing to remember about electronic components is that nothing is ideal. Components change values with frequency, current, voltage, and even physical size. And those changes may be nonlinear, adding a new level of complexity. Like a pilot, you need to know the limits so you stay within the envelope of safe performance.

Shielding to control EMI is a staple in modern electronics, playing a major role in military applications. Internal design practices can do much to control EMI in commercial and industrial electronics, but there is a limit to how much you can do. The EMI demands in military electronics are such that good internal design practices are inadequate - shielding is usually needed.

Electronic products are designed and tested to a variety of EMC requirements. Although specific requirements and test methods can vary by industry, ESD, transient immunity, RF immunity and RF emissions are evaluated for most products – certainly for all products that require a CE Mark.