I would like to use AD7946.
But, the output of Voltage follower(AD8629) before the ADC oscillated.
So, I have three questions.
#1 Is a capacitor(2.7nF) necessary? Is it possible to reduce the value or not to use a capacitor?(In Figure.25)
#2 How high can the resistance value(33Ω) be increased?(In Figure.25, Figure.28)
#3 When the resistance is set to more 250 Ω, what is the THD value?(In Figure.28)