Voltage follower consisting of op amp

In many typical circuit designs, the ad converter will have one before it. This follower is not necessary, in order to understand the role of the follower on the basis of their own circuit characteristics. First, the role of the follower is analyzed here:

The function of the voltage follower here is the impedance transformation function.

Impact One: The input impedance becomes very high, so that the impact on the input signal can be very small.

Impact Two: The output impedance becomes very low, the impact of the ad input impedance on the input signal can be very small.

As can be seen, the follower is very meaningful. Next, analyze your own circuit and the measured signal to make a decision whether to use a follower.

1, if the output impedance of the signal source is very small, then, the impact of one can be ignored.
2, if the input impedance of the ad is very large, then affect one and affect two can be ignored.

3, if two effects can be ignored, do not need to use a follower

4, there is an impact, you need to use a follower.