Inverting vs Non-inverting Amplifier: Difference and Comparison

Key Takeaways

1. Inverting amplifiers invert the input signal’s polarity, while non-inverting amplifiers maintain the same polarity as the input signal.
2. Non-inverting amplifiers have a higher input impedance than inverting amplifiers, which makes them better suited for applications requiring minimal signal distortion.
3. Inverting amplifiers can achieve a voltage gain of less than 1, while non-inverting amplifiers have a minimum voltage gain of 1.

What is Inverting Amplifier?

An inverting amplifier is also called an operational amplifier or inverting op-amp. A functional amplification circuit produces an output out of phase concerning its input by 180. It is used for the amplification of signals with the use of resisters and capacitors to perform different functions.

It has numerous ideal features like high bandwidth, unlimited open-loop gains, nearly zero resistance, and infinite input resistance. There are three inputs in an operational or inverting amplifier two for inputs and one for output. Among two terminals inputs, one is a positive (non-inverting) and the other is a negative (inverting) terminal.

Inverting amplifiers are used for mathematical operations on signals, such as amplification, addition, subtraction, integration, comparison, and filtering. In an inverting amplifier, the input signal is applied to the inverting end while the non-inverting terminal is grounded.

The inverting terminal is where the feedback signal is used. A closed-loop circuit is formed when the feedback signal feeds some output signals back to the input through resistors. Since the open-loop gain is so significant, it aids in lowering and precisely regulating the amplifier’s gain.

What is Non-inverting Amplifier?

It is an amplifier that generates an output signal, not changing its phase with the input signal, unlike inverting amplifiers. Inverting and non-inverting amplifiers are constructed from operational amplifiers and two resistors with different configurations.

Its output and input signal are in phase. It just amplifies the signal without altering its phase. It does not reverse the signal phase, contrary to its name. The input is applied to the op-amp’s non-inverting (positive) terminal in non-inverting amplifiers.

On the other hand, the inverting terminal is grounded through a resistor. Additionally, the feedback is used by its inverting terminal, sometimes known as negative feedback, to improve and gain control.

The non-inverting amplifier acts as a voltage follower circuit because it uses a negative feedback connection. This op-complementary amp’s device is the inverting op-amp, which produces an output signal 180 degrees out of phase. It has high input and low output impedance. This circuit is perfect for impedance buffering applications.

Difference Between Inverting and Non-inverting Amplifiers

Inverting and non-inverting amplifiers are used as circuits for signal amplification in electronics. Both have similar functions but are different in configuration, which is as follows.

1. Inverting amplifiers can invert the phase of a signal, whereas non-inverting amplifiers do not change the stage of the signal. 
2. In inverting amplifiers, the input signal is processed at the inverting terminal, whereas the non-inverting amplifier processes the signal at the non-inverting end. 

Comparison Between Inverting and Non-inverting Amplifier

Parameters of Comparison	Inverting Amplifier	Non-inverting Amplifier
Definition	It is a functional amplification circuit that produces an output out of phase concerning its input by 180.	It is an amplifier that generates an output signal, not changing its phase with the input signal, unlike inverting amplifiers.
Phase Difference	It converts the phase of the signal to 180.	It converts the phase of the signal to 0.
Input	Applied at the negative input terminal.	Applied at the positive input terminal.
Output	The achieved output is inverted.	The achieved output is non-inverted.
Ground Connection	The Positive input terminal is grounded.	The negative input terminal is grounded.

References

1. Boutin, N., 1981. Active compensation of op-amp inverting amplifier using NIC. Electronics Letters, 25(17), pp.978-979.
2. El-Queseny, R.E., Mahmoud, S.A. and Ibrahim, M.M., 2009, August. Modeling of CFOA based non-inverting amplifier using standard hardware description language. In 2009 52nd IEEE International Midwest Symposium on Circuits and Systems (pp. 37-40). IEEE.