What is an Integrated Circuit (IC)?

An integrated circuit (IC) is a circuit in which components such as diodes, transistors, resistors, capacitors, and so forth are automatically made part of a small semiconductor chip. In other words, an IC is a complete electronic circuit in which both active and passive components are assembled on a small chip of silicon. When we talk about active components we mean those which have the ability to produce gain such as transistors, whilst passive components are those that do not have the ability to generate gain e.g. resistors, capacitors and inductors.

It is important to note that, since the various components in an IC are fabricated as part of a small semi-conductor chip, individual components cannot be removed or replaced. This is in contrast to discrete assembly in which individual components can be removed or replaced. Note in a discrete circuit, separate components (produced independently), are connected to make up the electronic circuit.

Why use Integrated Circuits (ICs)?

The availability of low-cost ICs has almost rendered discrete circuits obsolete. Even though ICs have a number of advantages over discrete circuits, it is worth mentioning some of their shortcomings as we shall learn in our next section.

Advantages of Integrated Circuits

• Extremely tiny size due to fabrication of various circuit elements in a single chip of semiconductor material.
• Lesser weight and space requirement due to miniaturized circuit.
• Enhanced reliability since there are no soldered connections and there are fewer interconnections, which is usually a major cause of circuit failures.
• Low power consumption due to their small size.
• Enhanced response time and speed because of the fact that various components of an IC are located close to each other in or on a silicon wafer, which reduces the time delay of signals.
• The circuit layout is greatly simplified because integrated circuits are constrained to use minimum number of connections.
• Low cost because of the simultaneous production of many similar circuits on a single conductor wafer.

Shortcomings of Integrated Circuits

ICs have the following shortcomings:

• It is not possible to fabricate inductors and transformers on the surface of a semiconductor chip. Therefore, these components have to be connected exterior to the semiconductor chip.
• ICs work at fairly low voltages.
• They handle only limited amount of power.
• If a component in an IC gets damaged, the whole IC has to be replaced.

Related articles:

• The Basics of Semiconductor Physics as the Foundation of Electronics
• Semiconductor Diodes
• Metal Oxide Semiconductor FET (MOSFET)
• Electron/Vacuum Tubes vs. Semiconductor Devices
• How the Photoelectric Effect Influences Semiconductors
• Electronic IC Temperature Sensors