The errors you would be concerned about -
1) DAC linearity, gain error, tempco, PSRR, offset, Zout loading effects
2) Opamp offset, PSRR, gain error, offset tempco
Normally you take each parameter and convert it to LSBs,or ppm, then add them all up.
In case of noise added as RMS. Since DAC is only 8 bits, probably drop PSRR
as a consideration.
Some parameters not available, so that complicates a compete error analysis.
The you have complicating this an AC analysis if that is of concern.
Attached some useful references (more than you want to read).
All AtoD Error12.zip 12.1 MB