• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 46 subscribers
  • Views 143 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

ADS8689: Can internal reference drive an external circuit?

Arttu Rasanen
Prodigy 160 points
Part Number: ADS8689


Tool/software:

Hello TI,

my question is about the internal 4.096 V reference of the ADS8689 ADC. Can this reference be used to provide a stable reference for an external constant current circuit? Would it be suitable for driving the Vp input of the Improved Howland current pump mentioned in SBOA437[1]?

Thank you!

[1] www.ti.com/.../SBOA437

  • +1
    TI__Guru**** 181641 points

    Hi Arttu,

    I'm not familiar with the SBOA437 app note so I don't have any first hand knowledge of how well the internal reference of the ADS8689 will perform in this case.  That being said, we generally don't recomend using the internal reference of any ADC to drive external circuits without first buffering it to minimize loading which will impact the ADC performance.  Adding a buffer to the REFIO pin and applying that as 'Vp' above would be my suggestion.