Why opamp is called operational amplifier

An operational amplifier or op-amp is simply a linear Integrated Circuit IC having multiple-terminals. The op-amp can be considered to be a voltage amplifying device that is designed to be used with external feedback components such as resistors and capacitors between its output and input terminals.

It is a high-gain electronic voltage amplifier with a differential input and usually a single-ended output. Op-amps are among the most widely used electronic devices today as they are used in a vast array of consumer, industrial and scientific devices.

An op-amp has countless applications and forms the basic building block of linear and non-linear analogue systems. Some of the types of op-amp include:. Ideally, an op-amp amplifies only the difference in voltage between the two, also called differential input voltage. The output voltage of the op-amp V out is given by the equation:. Note:- Although an ideal op-amp draws no current from the source and its response is independent of temperature, a real op-amp does not work this way.

An op-amp only responds to the difference between the two voltages irrespective of the individual values at the inputs. External resistors or capacitors are often connected to the op-amp in many ways to form basic circuits including Inverting, Non-Inverting, Voltage Follower, Summing, Differential, Integrator and Differentiator type amplifiers. In linear circuits, the output signal varies with the input signal in a linear manner. Some of the linear applications are:. Thanks to op-amps and associated circuits, they have become an integral part audio amplifiers, waveform generators, voltage regulators, active filters, timers, A-D and D-A converters.

Op amp operational amplifier from Kausik das. You can view the video tutorial on Operational Amplifier is here. For the duration of this article, we're going to ignore these exceptions - they would get in the way of analyzing our voltage follower.

Instead of taking a direct measurement at Vin in our hyptothetical circuit, we'd measure instead at Vout. Using voltage followers provides a really easy way to interface different circuits that have different impedances.

What else can we do with opamps? As their name suggests, opamps are amplifiers. They can amplify signals by a certain ratio of input to output. This ratio is commonly referred to as the gain of an operational amplifier. In a perfect world, an opamp's gain would be infinite - so high that it could amplify any signal level to any other signal level.

This isn't the case in the real world, but we'll consider it a fact while we analyze the next circuit: an inverting amplifier. Let's walk through this circuit's operation step by step. First, let's apply our two opamp rules to figure out some node voltages of this circuit. What about the current going into and out of node V-? By Kirchoff's current law, we know that the sum of all currents at that node must be as follows:. Initially, this looks like it might take some work to solve, as this equation has three unknowns.

But does it? If you recall the opamp rules stated earlier, you'll see that we get one term of this equation for free: opamp inputs don't draw any current!

Therefore, we know that iV- is equal to zero. We can then rearrange that equation into the following form:. Since V- is tied to ground by the virtual short, Ohm's law allows us to substitute out these currents as voltages and resistances:.

Install the app. Contact us. Close Menu. Welcome to EDAboard. To participate you need to register. Registration is free. Click here to register now. Register Log in. JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding. When an operational amplifier is combined with an amplification circuit, it can amplify weak signals to strong signals. For example, such a circuit can be used to amplify minute sensor signals.

As the brain of electronic devices, MCUs operate according to input signals. By operating as a filter of input signals, the operational amplifier circuit is able to extract the signal with the target frequency. For example, when an operational amplifier circuit is used for voice recognition or in a voice recorder, it can extract frequencies close to the targeted sound while shutting out all other frequencies as noise.

An operational amplifier circuit can be tweaked to perform a broad range of functions such as arithmetical operations or signal synthesis. As noted above, an operational amplifier is almost never used alone. The following describes the operations performed by the operational amplifier in the circuit.