Yes, I think the current is around some uA level only. This thread may be able to help you regarding the actual measurement. https://ez.analog.com/message/114854?commentID=114854#comment-114854
We also have some recommended voltage reference parts…
Answering your questions:
1) No that is a pin for decoupling to ground for noise/stability reasons.The AD9834 has the reference input / output option - however for 1% tolerance I would advice using an external reference. The ADR280 or the ADR512…
The AD7173-8 has a buffer on it, I would recommend to use these rail-to-rail buffers. ADI has a ADR512 1.2V reference that I would recommend that is closest to your requirement of 1.1V. Or you check on the link below to check for other references…
I have some questions about ADI datasheet.
Our team are checking the datasheet because if the datasheet was changed we have to explain the changes.
And today , we found many datasheet was changed.
For just one example , AD8206 datasheet was changed…