My customer is using AD9208 and they are considering to change ac-coupled method to dc-coupled method for improving SNR/SFDR.
And as Figure 50 & Figure 56 in your datasheet , they know that dc-coupled configuration can be accomplished by External VCM and AMP configuration with some register settings
About these above comments, they have some questions.
(dc-coupled configuration using External VCM and AMP configuration)
1. Could they control the value of External VCM (Common Mode Voltage) the same as the full range of Common mode voltage (Vcm : 1.32V to 1.52V) in table 1?
2. If they can do above thing, how do they control these values (from 1.32V to 1.52V)?
3. If they can't do this, would you share limitation of controllable value of External VCM?
4. If you have any reference schematic with External VCM and AMP configuration, please share your reference schematic to them.
Or please share your recommended part and circuit for this configuration.
5. For above things (Improving SNR and SFDR using dc-coupled), if you have any opinions, please advise them