Hi Bob, In section 8.5.2 of the ADS1220 user manual there is a description of the 24 bit binary twos compliment data output from the device. I attempted to calculate the expected resolution with my application and wanted to ask if you agreed with my results if you don't mind. For my application using the 50uA current source my Vref to the ADS1220 should be 1.245V. This is based on 50uA through the 24.9K ohm fixed resistor in the 109 thermistor probe. Based on equation 16 in the data sheet (and assuming a gain of 1 for starters) I calculate a resolution of 1.484 X10^-7 Volts/count. With 50uA of drive current my differential thermistor voltage should vary from 0.99515V @ 10 degrees C and then 0.43885V @ 28 degrees C. This equates to a deltaV of 0.5563V which I think would result in a span of 3748259 counts. Than you and I appreciate your input. -Sean M
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