in the datasheet it is recommended for the Rf resistors not to be higher than 1K.
If I can accept:
- reduction of the dynamic due to the input current flowing through the Rf
- increased differential error due to Rf mismatch
I'm assuming I can use Rf higher then 1Kohm
- What would be a limit I shell use as "no go"?
Currently the plan would be to test 5-10Kohm.
- Would that work for the ADC1220 by accepting the limitations?
From settling time/sampling frequency I'm assuming some limitations as well.
- Would the input current for the ADC be guaranteed by using the higher resistors?
The plan would be to use PT1000 with a ratiometric configuration.