I did a brief search but could not find a thread that covered this issue.
I am using the DAC of a 128a1u. I need an output from 0-2.5VDC. Even with no load, I cannot get the output above 2.3VDC. I have tried both an external reference of 2.5VDC and the AVCC (3.3VDC) as reference.
I recall some discussion of this being an inherent problem. Is this the case?