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Maybe you can make me clear whether the AC couple of the differential ADC just eliminate the DC (or noise) of the signal source, but there also is intrinsic DC of the ADC devices?
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AC coupling just breaks the DC path from the signal source to the ADC pins.
The DC value on the ADC pins is then determined by the ADC. Ideally the ADC manufacturer designed the part so that it defaults to a DC level that corresponds to the mid-range of the ADC output codes. However, there is no guarantee of that, so you have to check. For example, I have used ADCs with track-and-hold DC offset control, so that you can adjust the DC level of an AC coupled ADC.
Cheers,
Dave
Honored Contributor
