Q
I want to use the AD9826 to sample pixel data coming from a NIR-sensor. The
pixel data is between 1.2V and 3.2V. Is it possible to use external Bottom- and
Top-references (1.2V and 3.2V) to get the full 16bit resolution for the pixels?
If not, how do I have to configure the AD9826 to have the best
performance/resolution?
A
Yes, it is possible to modify the reference voltage swing of the AD9826 (and
9814, 9822, 80066) by using an external reference. Please see the attached app
note as a recommendation- the op-amp in this note is a little old, and chosen
for low cost, so of course you could substitute a higher performance amp if you
wish. The main point is the CAPT and CAPB pins must be driven using a buffer,
they should not be connected directly the R-divider.