Abstract: A printed circuit (PC) board-mountable ferrite electromagnetic interference (EMI) filter (702, 1003, 1003") for PC conductors (701, 1001, 1002) of a printed circuit (PC) board (700, 1000) that accommodates large numbers of PC conductors, and is cost-effective. One embodiment of the EMI filter is used with a PC board (700) that routes PC conductors (701) in a step-function (i.e., a "U"-shaped) pattern. The EMI filter comprises a ferrite body (702) that defines two parallel passageways (708, 709), i.e., has a figure-8 shape in cross section. The portion (710) of the PC board that defines the PC conductor portions extending in the one direction lies in one passageway, whereas the portion (711) of the PC board that defines the PC conductor portions extending in the other direction lies in the other passageway. A different embodiment of the EMI filter is used with a PC board (1000) that routes sets (1001, 1002) of PC conductors in a cross-hatch (i.e.

Abstract: A printed circuit (PC) board-mountable ferrite electromagnetic interference (EMI) filter (702, 1003, 1003") for striplines (701, 1001, 1002) of a printed circuit (PC) board (700, 1000) that accommodates large numbers of striplines, and is cost-effective. One embodiment of the EMI filter is used with a PC board (700) that routes striplines (701) in a step-function (i.e., a "U"-shaped) pattern. The EMI filter comprises a ferrite body (702) that defines two parallel passageways (708, 709), i.e., has a figure-8 shape in cross section. The portion (710) of the PC board that defines the stripline portions extending in the one direction lies in one passageway, whereas the portion (711) of the PC board that defines the stripline portions extending in the other direction lies in the other passageway. A different embodiment of the EMI filter is used with a PC board (1000) that routes sets (1001, 1002) of striplines in a cross-hatch (i.e.