I am having some serious noise issues with CN0540/ AD7767 picking up too much noise:
1. There are low frequency (<few Hz) fluctuations. Setting Vocm to 1V1 or 0V9 seems to reduce those but not entirely. While using Vocm =2V5 or mid supply make output constantly jump up to +/-1.5v making the whole setup unusable . Disconnecting internal constant current supply seems to eliminate the issue . Wrapping the entire board in aluminum foil and connecting to board GND also solves it, even with the internal current source enabled.
2. There is a huge spike right at 60Hz mains frequency (30Db above the noise floor). It persists even with output disconnected. Removing the jumper to constant current supply cuts the 60Hz peak to roughly15Db above the noise floor. Shielding the board and connecting the shield to the board ground eliminates this spike even with the current source enabled, however connecting coaxial cable with IEPI to the input brings the 60Hz back up.