Hi, yes they used common mode chock with the external power supply 12 V which is U16 in the picture in first post then the filtered 12 V is supplied to several dc-dc buck converters to generate low voltages for kintex development board, there they used ferrite beads to power the dc-dc converter but not used at the outputs where they have inductors and capacitors.
The use of common mode chock and ferrite beads is to reduce EMI, right ? but how do we select these devices.