HI
we are designing system with RS422 interface.
we deciided to have ISO1412B RS422 transceiver with isolation IC in our design.
i have studied the datasheet and specified that 2 separate power supplies and 2 separate ground are required.
In my PCB, i am having only one 3.3V voltage supply and one Ground.
In Reference design, i have seen other circuit is used i.e. SN6505, TPS76350
Whether both power supplies, grounds should be isolated or not.
regards
K.Jayalakshmi