ADM3055E with dual power supplies


I would like to know whether an ADM3055E can be used without using the internal isolated DCDC converter which allows operation with a single 5V power supply, and instead use 3V3 supply on the Bus side (VCC + VIO), and an external supply (isolated from the first) on the other side of the transceiver (VISOIN pin)?

If so, should I leave VISOOUT floating? What would be the requirements for the input supply on VISOIN pin?