Complete Electronics Self-Teaching Guide with Projects

The Operational Amplifier

43 The operational amplifier (op-amp) in use today is actually an integrated circuit (IC). This means that the device has numerous transistors and other components constructed on a small silicon chip. These IC op-amps are much smaller and, therefore, more practical than an amplifier with equivalent performance that is made with discrete components.

You can purchase op-amps in different case configurations. Some of these configurations are the Transistor Outline (TO) metal package, the flat pack, and the dual in-line pin (DIP) package. You can also find two op-amps (dual) or four op-amps (quad) in a single IC.

Their size, low cost, and wide range of applications have made op-amps so common today that they are thought of as a circuit device or component in and of themselves, even though a typical op-amp may contain 20 or more transistors in its design. The characteristics of op-amps closely resemble those of an ideal amplifier. Following are these characteristics:

• High input impedance (does not require input current)
• High gain (used for amplifying small signal levels)
• Low output impedance (not affected by the load)

Questions

A. What are the advantages of using op-amps? _____

B. Why are op-amps manufactured using IC techniques? _____

Answers

A. Small size, low cost, wide range of applications, high input impedance, high gain, and low output impedance.

B. Because of the large numbers of transistors and components that are required in the design ...