For DC/DC converters with high input and output currents, the choice of the appropriate capacitor technology, power inductors, switching frequency and semiconductors is decisive for the resulting efficiency. However, a switching regulator with high efficiency is only ready for the market if it also complies with all the necessary EMC directives, or the end product in which it is used. For this purpose, suitable filters often have to be incorporated at the input and output in order to reduce interference emissions. But with high input and output currents, it is difficult to find a compromise between efficiency, size, attenuation and cost of the filters as well as the actual power stage. Using a 100◦W buck-boost DC/DC design as an example, we will describe the basic considerations, layout hints and components needed to achieve such a compromise.