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ADS8694: Using a 2.048V External Reference

Part Number: ADS8694

Can I use an external Vref of 2.048V (or 1.024V) with the ADS8694 ? The datasheet talks of an external Vref, but limits it to only 4.096V.

I would like to get an input Voltage range of +/- 1.28V (with a 2.048V external Vref) or a +/-0.64V (using a 1.024V external Vref). Is this possible with the ADS8694 ?

Best regards,


  • Hi Raj,

    The datasheet only defines operation with a +4.096V external reference voltage so while the device may function with a lower reference voltage it's difficult to predict the performance over temperature and lifetime operation.  One option would be to use the +/-2.56V output mode and use a limited code range to achieve the range you desire.  

  • Hi Collin,

    Thank you for the quick response. My application requires me to use the full 17-bit span (for measuring 0V to +0.64V). I need the full 17bit resolution.

    I figured the other external Vref voltages might work, but have not been full tested & characterised. For the moment, I am considering Amplifying my input voltage to the ADC input to make use of the +/-2.56V range. This will however add additional noise and voltage offsets. Not the best solution, but is an option.

    I would love to hear from someone who has used the ADS8694 with an external Vref lower than the recommended 4.096V.

    Best Regards,