The AD9268 obviously has some input protection diodes at the analog inputs (AIN+/-).
The abs. max. voltage ratings are given in the datasheet.
But what is the abs. max. rating for the protection diodes' current capability?
Knowing this is necessary when the max. voltage can not be ensured but current can be limited with series resistors.
As already stated in another discussion external clamping diodes are often not an option.
In our case we use an ADA4938 with +3V and -2V supply as driver and 48 Ohms of series resistors.