Typical voltage follower circuits are used as which of the following?

Typical voltage follower circuits are used as which of the following?

• A. Oscillators
• B. Impedance matching devices
• C. Power amplifiers
• D. Filters

Answer: (B)

A voltage follower provides unity gain while acting as a buffer between stages, thanks to its very high input impedance and very low output impedance. This combination means the source is hardly loaded at all, and the load is driven without pulling the source voltage down. That makes it ideal for impedance matching: it lets a high-impedance source feed a low-impedance load without altering the signal level. It isn’t an oscillator because it doesn’t generate a periodic waveform. It isn’t a power amplifier, since the gain is unity and the circuit is not intended to deliver large power to a load. It isn’t a filter, as it doesn’t shape the signal’s frequency content. The strength of a voltage follower is precisely in buffering and impedance matching between stages.

A voltage follower provides unity gain while acting as a buffer between stages, thanks to its very high input impedance and very low output impedance. This combination means the source is hardly loaded at all, and the load is driven without pulling the source voltage down. That makes it ideal for impedance matching: it lets a high-impedance source feed a low-impedance load without altering the signal level.

It isn’t an oscillator because it doesn’t generate a periodic waveform. It isn’t a power amplifier, since the gain is unity and the circuit is not intended to deliver large power to a load. It isn’t a filter, as it doesn’t shape the signal’s frequency content. The strength of a voltage follower is precisely in buffering and impedance matching between stages.