I used XTR105 with RTD, piezo bridge and potentiometer without problems.
In the new application I connected a humity sensor (Homeywell HIH-4000-001) to the Vin inputs of XTR105, the prototipe works OK.
I checked again the values and I found the Vin+ signal start from 0.67V(RH 0%) to 3.24V (RH 100%), Vin- is fixed to 0.67V, all respect Iret pin.
I've always thought that the Vin+ and Vin- must be 1.25V greater than Iret voltage, like datasheet specification.
Where am I wrong?