I am fairly new to multi-channel ADC sampling.

I have a ADS7828 and trying to sample all 8 channels - just measure all of
them once a second.

I found that if I sample only one channel, I get very little noise and the
values look reasonable.

But if I sample more than just 1 channel, it seems like the value of one
sample has some kind of "leakage" to the value of the next. By increasing
the voltage on channel 1, I actually measure a voltage increase on channel
2. The "leak" occurs all the way down the chain.

So what should be something like:

1024  0  0  0  0  0  0  0
Is giving:
1024 1024 950 870 780 690 600 550

Sometime it's even showing a bigger rollover than that:
1024 1024 1024 1022 1020 1017 1015 1012


1 Hz from each channel every second is well below the ability of the chip,
but the data sheet doesn't address anything like this. WTF am I doing
wrong? Is it an error in my I2C communication? The actual wiring? Bad chip?

I'm sending Single-ended input mode, internal ref off, ADC alway on, with
an external reference of 5V:
0b1xxx01xx

Any help would be appreciated.
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