Is it possible to create a split isolated supply with the isoPower devices
(i.e. ±3.3V or ±5V).
This can be done one of two ways.
1) Use the ADuM347x or ADuM3070. These devices use external transformer
so multiple windings and negative rails are possible.
2) Use an external charge pump. With the standard isoPower devices, a
charge pump can be used for generating a negative rail.