As with all modern electronics, EMC is an important consideration. Railways have their own EMC standard called EN50121-3-2 for rolling stock. In addition, many of the industrial EMC levels specified by EN55011 apply. To meet these EMC requirements, an EMC filter is needed to protect the DC/DC converter and absorb any conducted emissions. RECOM gives suggested EMC filter values in their datasheets to meet EN50155 as well as industrial Class A and Class B requirements.