Simple Voltage Follower Circuit Using op amp 741 designed to give unity gain output. We know voltage follower circuit will give the output same as input signal but the output gain only increase. Voltage follower amplifier can also called as Unity gain amplifier or Buffer amplifier.
We commonly using IC LM741 as a operational amplifier and the following circuit also designed by using op amp 741. IC 741 is a dual inline packed 8 Pin integrated circuit. It can provide high gain output. It has two input terminals called Inverting input (Pin 2) and Non Inverting input (Pin 3) then one output terminal (Pin 6).
Op Amp 741 Pin details
This IC741 can operate by using dual power supply or battery power supply and also it can operate in maximum 22V. This IC can works as general purpose operational amplifier and Comparators, Multivibrators , Integrator or Differentiators, Active Filters etc..,
Voltage Follower Circuit Diagram
- Operational Amplifier IC LM741
- Variable Resistor 10KΩ
- Resistor 1KΩ (For testing)
- 9V Battery
- Input signal source (Use function generator)
Construction & Working
Input signal is applied to the Non inverting terminal (Pin 3) and Inverting terminal (Pin 2) is connected with output (Pin 6) to make negative feedback. Bias pins are connected with battery and output is connected to the 1KΩ Load resistor.
Input impedance of operational amplifier IC 741 will be very high (upto 1MΩ) when we implement in voltage follower or buffer amplifier circuit. Due to the high input impedance very low current will be drawn from input source and then gives high current output to the load. Here output impedance will be very low.
We can calculate current, Voltage and Resistance by using following ohm’s law.
Current = Voltage / Resistance
Here the voltage follower gives same output voltage as input voltage but it draws low input current from input source due to high input impedance and gives high gain output due to the low output impedance. Due to same level input and output it is called as unity gain amplifier.