Introduction
Welcome to our blog post on comparing inverting and non-inverting op-amp circuits, where we will explore the differences and similarities between them in a fun and engaging way. Both circuits are essential components of modern electronics, and they each have their unique characteristics that make them useful in various applications. We'll provide factual information, so let's get started!
Op-Amp Basics
First, let's briefly discuss operational amplifiers, commonly known as "op-amps." Op-amps are integrated circuits that are widely used in electronics. They are linear devices that have a high differential gain, which means that they amplify the difference between two input voltages.
Inverting Op-Amp Circuit
The inverting op-amp circuit is one of the most basic and widely-used circuits. It has an input voltage at the negative terminal and a feedback voltage at the positive terminal. The output voltage is inverted and amplified, hence the name "inverting." Its gain is given by the ratio of the feedback resistance to the input resistance.
Non-Inverting Op-Amp Circuit
The non-inverting op-amp circuit has a positive input at the non-inverting port and a negative feedback at the inverting port. The output voltage is non-inverted, and the circuit has a voltage gain of (Rf+R1)/R1, where R1 is the input resistance, and Rf is the feedback resistance.
Comparing the Op-Amp Circuits
Now that we have a basic understanding of both circuits let's compare them!
Voltage Gain
The voltage gain of the inverting op-amp circuit is given by the ratio of the feedback resistance to the input resistance. On the other hand, the voltage gain of the non-inverting op-amp circuit is (Rf+R1)/R1.
Input Impedance
The input impedance of the inverting op-amp circuit is equal to the input resistance R1. In contrast, the input impedance of the non-inverting op-amp circuit is infinite since there is no current flowing into the non-inverting input.
Output Impedance
The output impedance of the inverting op-amp circuit is low and mainly depends on the op-amp's output impedance. On the other hand, the output impedance of the non-inverting op-amp circuit is high and primarily depends on the value of the feedback resistor.
Common Mode Rejection Ratio (CMRR)
The CMRR measures the ability of an op-amp circuit to reject common-mode signals. In the case of the inverting op-amp circuit, the CMRR is limited by the input impedance. In contrast, the CMRR in the non-inverting op-amp circuit is determined by the gain.
Conclusion
In conclusion, the inverting and non-inverting op-amp circuits have their unique characteristics, as we’ve unraveled them in this blog post. The inverting circuit has a voltage gain that is typically less than the non-inverting circuit, but it’s less sensitive to load changes. On the other hand, the non-inverting op-amp circuit has a high input impedance and is suitable for applications that require a buffer stage.
We hope this blog post has been informative and engaging!
References
- Op Amps for Everyone, Ron Mancini, Texas Instruments, 2002
- Sedra, Adel S., and Kenneth C. Smith. Microelectronic Circuits. Oxford University Press, 2014.
- Basic Electronics: Theory and Practice, Sean Westcott and Jean Riescher Westcott, 2017.