I've built a custom board with 4x ADS5272 on it and I'm finding some strange behavior in normal ADC mode. When I first power the chips up, they all output a fixed pattern on their serial data outputs. Each channel has something different and when I reset the chip, it sometimes changes. I don't have any input connected yet, but I would expect there to be enough randomness to at least toggle the last few bits randomly.
I've used the command interface to set it into the two test pattern modes, and those function as expected. When I set it back into normal ADC mode, I get the same behavior (outputting a fixed data value).
What's going on here?
