I'd like to know the following sentence on page 46 in detail.
'ADC0PGA[3:0].  = ADC0 gain of 1. Buffer of negative input is bypassed.'
Does it mean that the negative input pin connect to switched-capacitor input through the mux?
Can't the negative input pin connect to high impedance source directly when PGA is used with gain of 1?
I wonder if I should drive with an op amp when it is used with gain of 1.