Schaffner fn 406 ultra compact emc filter pcb mounting schaffner emc fn 406 3 02 a 3a single phase emc filter in a compact pcb mounting body the features and performance of these components make them suitable for a wide range of applications such as single phase power supplies switch mode power supplies test and measurement equipment small to medium size machinery schaffner emc fn 406 3 02 3a ultra compact emi pcb filter