EMI Filter

This article presents the EMC design techniques for electric vehicle powertrain modules. High voltage EMC regulations for powertrain modules are reviewed first to help understand associated design challenges. The design techniques are then demonstrated in detail to help engineers design a module that will pass the EMC requirements in the test chamber.

There has to be a better way of specifying EMI filter performance – one that shows a filter’s effectiveness in real-life situations. It turns out there is a better alternative test method that fulfills this need. This method is the insertion loss test method for non-50Ω systems, located in Annex C of the second edition of EN 55017 (a.k.a. CISPR 17).

The electronic industry has embraced simulation to address several complex design challenges, but reliability is still mostly dealt with best design practices and tested with prototypes. In this article, we present how modeling and simulation approaches can help designers perform virtual prototyping and uncover reliability issues especially EOS/ESD before going for physical prototypes.

Single electromagnetic pulses like lightning, ESD, powerline transients, NEMP, etc., are generally described in time domain, while filters and shields are practically always characterized in frequency domain. This article describes a quick and handy formula and nomogram providing a fair estimate of the filter or shield response to a conducted or radiated threat.

Grounding is often viewed from separate points of view - safety, ESD, or EMI.  This article combines all these aspects together so that practitioners can address grounding at the factories and in the laboratories in a comprehensive way.