Based on my correspondence with the designer, there are 3 separate filters. One is for Power, one is for ground and, the other is for Data, the latter being a common mode type. You must also understand or appreciate, that the ground is shared by both the power and data signaling. And thus the two are necessarily intertwined. This must be accounted for in the design of the filtering. There is PCB board in the unit, I know of no ferrite core.