Amplifîyer OP ya Voltage Follower: Yê çi ye?

Voltage Follower çi ye?

Voltage follower (bêjîn buffer amplifier, unity-gain amplifier an jî isolation amplifier da) ji op-amp circuit e ku output yekê voltage yekê input voltageya taybet dike (wê "follow" input voltageyê). Naha voltage follower op-amp input signal bikar nîne û voltage gain yekê heye.

Voltage follower attenuation an amplification nekirin - tenê buffering kirin.

Voltage follower circuit high input impedance yek e. Eta xasaya wê bixweber biguheztin yên din derve yên di navbera input û output signalyan de.

Voltage follower circuit li vir dibistin.

Qanûnê herêmser a ku voltage follower ya bêjîn Ohm’s law.

Wê dîsa ku current yek ê circuit current yekê voltage yekê û resistance yekê.
We dîsa voltage followers high input impedance (û high resistance).

Lê dema me circuits bi high impedance biberin, serfiraz bibe ku me heman dikarin bisperînin ku şeşeyên low impedance dike.

Input impedance low û resistance low dike, R formula Ohm's law yekê be small.

V fixed dike, vê wisa large amount of current load bi low-impedance (resistance) bide.

Naha circuit large amount of power from the power source, resulting in high source disturbances.

Heta bêt bibirin same power to a voltage follower circuit.

Voltage follower circuit li vir dibistin.

Dikarin biceribin ku output connected to its inverting input.

This connection forces the op-amp to adjust its output voltage to equal the input voltage.

The output voltage hence “follows” the input voltage.

As mentioned, a voltage follower is a type of op-amp with a very high impedance.

More specifically, the input side of the op-amp has a very high impedance (1 MΩ to 10 TΩ), while the output does not.

Now Ohm’s law still needs to hold true.

So if we keep the voltage the same on the input and output side, and we significantly drop the resistance… what is going to happen to the current?

That’s right: the current skyrockets.

A voltage follower keeps the voltage the same—we didn’t say it kept the current the same too!

While a voltage follower has unity voltage gain (i.e. it equals one), it has a very high current gain.

So on the input side: very high impedance, and very low current.

And on the output side: very low impedance, and very high current.

Voltage stays the same, but the current goes up (because impedance went down between the input and the output side).

As mentioned: the input impedance of the op-amp is very high (1 MΩ to 10 TΩ).

With such a high input impedance, the op-amp does not load down the source and draws only minimal current from it.

Because the output impedance of the op-amp is very low, it drives the load as if it were a perfect voltage source.

Both the connections to and from the buffer are therefore bridging connections.

This results in reduced power consumption in the source, and less distortion from overloading and other causes of electromagnetic interference.

Voltage Follower Gain

A voltage follower has a voltage gain of 1 (unity), because the output voltage follows the input voltage. Although the voltage gain of a voltage buffer amplifier is approximately unity, it provides considerable current and power gain. Despite this it is common to say that it has a gain of 1—referring to the voltage gain (the equivalent 0 dB).

Voltage Follower in Voltage Divider Circuits

In every circuit, voltage is shared or distributed to the impedance or resistance of the connected components. When an