About AD8133, the datasheet does not define if the exposed pad shall be connected to a defined reference (i.e. ground plane).
For example, other similar IC like AD8147 and its evaluation board example (CN0275) define in the datasheet that referenced ground plane shall be connected to the exposed pad.
Currently, AD8133 recall CN0275 as reference: it seems that exposed pad shall be referenced to something.
Let me know the correct connection for the exposed pad.
Thanks in advance