Internal calibration of AD7731


I have read through the datasheet and, I am not sure if the AD7731 should be disconnected from the analog signal when performing internal zero scale and internal full scale calibration.

For example, channels 5 and 6 in full differential mode, AIN- driven with a 2.5v voltage source (LM4140) and AIN+ driven from a custom sensor through an OpAmp. REF_in- is tied to ground and REF_IN+ is 5v

Should I disconnect the 2.5v and the sensor OpAmp from the device for calibration?

Should I disconnect only the sensor OpAmp?

Should I not disconnect anything for calibration?

Thanks for your input.

  • 0
    •  Analog Employees 
    on Feb 16, 2016 10:48 PM

    Hi Levon,

    It is alright not to disconnect anything during calibration as long as the signals connected to the analog input pins of the device are within the specified limits and noise/interference free.



  • 0
    •  Analog Employees 
    on Aug 2, 2018 3:22 PM
    This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

    Thank you,
    EZ Admin