Q8. Why are the Analog input buffers required for voltage measurements AD4111/AD4112/AD4114/AD4115?
The Analog input buffers should be enabled for voltage Analog inputs as these provide a low source impedance to the sampling ADC. If these buffers were disabled, then a large resistance would exist. This combined with any parasitic capacitance from the resistive front end driving the ADC input will result in a very large gain error.