AnsweredAssumed Answered

AD7124 : use with a PRTD100 1/3 DIN sensor

Question asked by AaronEco on Feb 17, 2017
Latest reply on Mar 28, 2017 by AaronEco



I want to use an AD7124 ADC with a PRTD100 1/3 DIN 4 wires sensor. This sensor has an accuracy of 0,1°C and I want to keep this accuracy at the end of my measuring chain. I have some questions:

It looks like the accuracy of the excitation current sources is 4%. Is that right ?

I also want to know if it is possible to get the voltage of the Rref resistor. Maybe I can link two analog inputs at its end to retrieve this value on the output.

Finally, I don't really know how to choose my resistor reference value. If the current flowing through my sensor is 0.250mA, the voltage accross the sensor will move from 25mV to 34.5mV between 0-100°C with a pitch of 0.032mV for 0.1°C.


Thank you for your help !