The Voltage Follower
Voltage Follower
The Basics
The voltage follower, like the comparator, requires no components other than the op-amp itself. The voltage follower is typically used as a buffer; whatever circuit is connected to the output will have essentially no effect on the circuit attached to the input. Either of the inputs is connected directly to the output. The other is connected to the part of the circuit where you would like to monitor the voltage (see the schematic and simulation below).
Schematic:
Simulations:
Sweeping Vin
Gain Derivation (sort of)
There isn’t really a gain derivation. Just remember, the output equals the input just as the name suggests (and also the reason there is only one trace visible in the sim).