EMI control can be a complex design task that is dependent on many factors. However, a reduction of differential- and common-mode conducted noise created by the power converter(s) can be achieved by using either passive or active filters. In AdvancedTCA and telecom systems, the redundancy requirement of field replaceable boards into functioning shelves drives the need for a current inrush limiting function on each board. This function is generally referred to as hot swap. This article focuses on the advantage of using certain core hot swap elements, for example, the FET, as the series element in the active differential filter and the current limit sense element for the filter control signal to achieve active EMI control. Using this approach, the designer gets added value: superior noise attenuation and additional savings in board space.