## 4 – Op Amp: Ideal and real characteristics

In this lesson we will see what are the main characteristics of an Operational Amplifier.

We will try to understand what are the values that should characterize the ideal case.

And, finally, we will see how much the real case is close to the ideal case.

An ideal operational amplifier should have the following four characteristics:

## 3 – Op Amp: Characteristic Equation And Curve

The mathematical model that describes the behavior of any Operational Amplifier is expressed by the following equation: $V_{OUT}=A\cdot \left( V_{+}-V_{-} \right)$

Its meaning is simple: output voltage is equal to the difference between input voltages amplified by a positive factor A (called open-loop gain).

## 2 – Op Amp: Schematic Symbol

Operational Amplifier, like any electric or electronic component, can be represented in diagrams by a schematic symbol.

There are more than one schematic symbol and this happens because sometimes it is not necessary to outline all the connections of an Operational Amplifier.