The Function of an Op-Amp with Inverting Input Terminal Shorted to Output Terminal and Grounded

An operational amplifier, commonly referred to as an op-amp, is a versatile and widely used electronic component in various applications. It is typically used to amplify and process analog signals. In this configuration, the inverting input terminal of the op-amp is shorted with the output terminal and also grounded, while a voltage signal V1 is applied to the noninverting input terminal of the op-amp.

Voltage Follower
The function of the op-amp in this configuration is that of a voltage follower. A voltage follower, also known as a unity-gain amplifier, is an op-amp configuration where the output voltage follows the input voltage. In other words, the output voltage is the same as the input voltage, but with a high current capability.

This configuration is commonly used when a high input impedance and low output impedance are desired. The op-amp acts as a buffer between the input and output, ensuring that the input signal is not affected by the load connected to the output.

How it Works
When a voltage signal V1 is applied to the noninverting input terminal, the op-amp tries to adjust its output voltage to make the voltage at the inverting input terminal equal to the voltage at the noninverting input terminal. However, since the inverting input terminal is shorted to the output terminal and grounded, the voltage at the inverting input terminal is always zero.

As a result, the op-amp adjusts its output voltage to zero, making it a virtual ground. This virtual ground at the inverting input terminal ensures that the input signal is not affected by the op-amp's internal impedance. The op-amp amplifies the input voltage with a gain of one and produces an output voltage that is an exact replica of the input voltage.

Advantages and Applications
The voltage follower configuration offers several advantages, including:

1. High input impedance: The op-amp presents a very high input impedance, ensuring that the input signal source is not loaded or affected by the op-amp's impedance.

2. Low output impedance: The op-amp provides a low output impedance, allowing it to drive low impedance loads without significant signal degradation.

3. Unity gain: The op-amp has a gain of one, meaning that the output voltage is exactly the same as the input voltage.

The voltage follower configuration is commonly used in various applications, such as:

- Impedance matching: It is used to match the impedance between different stages of a circuit, ensuring efficient transfer of signals.

- Buffering: It is used to isolate the input and output stages of a circuit, preventing loading effects and maintaining signal integrity.

- Signal conditioning: It is used to prepare analog signals for further processing or interfacing with other components.

In conclusion, when the inverting input terminal of an op-amp is shorted to the output terminal and grounded, while a voltage signal is applied to the noninverting input terminal, the op-amp functions as a voltage follower. It provides a high input impedance, low output impedance, and unity gain, making it suitable for applications requiring signal buffering, impedance matching, and signal conditioning.