Hi,
* at first you have to decide your max. temperature range.
* then calculate min. and max. voltage. According resistance tables, constant_current and min and max temperature.
--> this is the input voltage range of your OPAMP
If i´m correct, then the ADC input voltage range is 0V ... 1.2V
* devide ADC input voltage range by OPAMP input voltage range --> this gives the desired gain of the OPAMP circuit.
* then you need to adjust offset, so that with min. input voltage you get 0V output voltage. (assuming non inverting circuit)
* in the software you need to calculate this back: first you have to correct offset, then adjust gain(best with one multiplication of "Kelvin/LSB")
With a 10 bit ADC you get a temperature resolution of: temperature_range/1024.
Klaus