Ideal Operational Amplifiers

CURRENT – Ideal Operational Amplifiers Introduction

Ideal Operational Amplifiers Introduction

The operational amplifier is an important electronic device that serves as a building block for relatively complex circuits.

In this chapter, you will learn:

  • The characteristics of ideal operational amplifiers as circuit elements.
  • How to use operational amplifiers to build inverting and non-inverting amplifiers.
  • Input and output characteristics of operational amplifier circuits.
  • Circuit models used to represent operational amplifiers.
  • Design approaches applied to multiple-input amplifiers.
  • How to design more complicated operational amplifier circuits to perform a variety of functions.


The rapid expansion of requirements for smaller, lighter and more complex circuits resulted in the need to place hundreds of transistors on a single chip. Whenever more than one element is placed on a single chip, the resulting device is known as an integrated circuit (IC).

Integrated circuits are classified according to their complexity.

The term, small scale integration (SSI) is used to describe those chips composed of less than about 50 elements. If a chip contains over 50 but less than about 300 elements, the term medium scale integration (MSI) is used. If the number of elements is over 300 but less than about 1000, the circuit is known as large scale integration (LSI). Very large scale integration (VLSI) refers to those chips with more than one thousand elements but less than about one million elements. Circuits with more than one million devices per chip are known as ultra large scale integration (ULSI). Linear integrated circuits (LIC) can replace standard circuits, and these LICs are then used as building blocks for more complex systems. Integrated circuits can be analog or digital depending on the forms of the input and output waveforms.

One of the most utilized analog integrated circuit is the operational amplifier (op-amp)Ideal operational amplifiers have infinite gain, infinite input impedance and zero output impedance. Practical operational amplifiers have performance characteristics that closely approach those of ideal operational amplifiers.