Voltage Follower with Op-Amp
This is a emitter follower circuit. This circuit is popular with name buffer circuit. This circuit has gain of 1, so the input voltage is not amplified. Here is the schematic diagram of the circuit:
This circuit is a noninverting amplifier with R2 zero and the R1 infinite. This circuit has low output impedance and high input impedance. The LM310 is the special op-amps designed as followers.