Linearity, stability of the AD590?
Regarding AD590, the part should work correctly as long as the voltage is
maintained within specifications i.e. must ensure a minimum voltage of 4V
across V+ and V-.
The part is specified with a 1k resistor. If you use a 10k resistor, for
instance, then the voltage across the resistor is 298.2uA x 10k =2.98V.
Therefore V+ needs to set to 6.98V to ensure correct linearity. Stability
should not be an issue with a resistive load.