I am planning on using the LNKSwitch as shown in the RDR506 reference design to supply 12V for the HiperPFS-3 and HiperLCS as shown in the DER394 and RDR239 reference designs.
My concern is the grounding and EMI filtering.
The ground of the 12V for the RDR506 is connected only through a diode to the the AC input.
It looks as if in the DER394 reference design they specificially seperate the 12V ground from the input AC and the 385V DC output.
I am concerned about connecting the grounds between the DER394 and RDR-239 as the RDR-239 has a split ground plane as well.