The presence of non-isolated DC-DC buck converter plays a crucial role in electrification of aircraft, bio-medical and automotive devices. To obtain output devoid of interference from external sources, maximizing specific power or power density of the EMI filter is necessary. This requires a filter that is capable of eliminating or filtering these unwanted surges or spikes in the power converters. In this paper an EMI filter is placed in the buck converter operating with common mode/differential mode. An EMI filter is first designed taking into account the impact of interference in the power rails and the ground rails. The model is implemented and the output of the buck converter in the presence and absence of the proposed EMI filter is analysed.