Do I need to use a buffer for the Analog Inputs if I am reading DC Values?
The impedance of the source affect what the AD7699 input can see. As describe in the datasheet analog inout, during ADC acquisition phase, the AD7699 inputs is modeled as a parallel Cpin and a series connection of Rin and Cin with Rin typically 400ohm. An impedance from a DC source can interact with the input impedance of the ADC that affect or attenuate what the ADC can see from its inputs. A buffer is recommended to provide low impedance to the ADC input.
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