Integrated Circuits Help

By — McGraw-Hill Professional
Updated on Sep 11, 2011

Introduction Integrated Circuits

Most integrated circuits (ICs) look like plastic boxes with protruding metal pins. Common configurations are the single-inline package (SIP), the dual-inline package (DIP), and the flatpack . Another package looks like a transistor with too many leads. This is a metal-can package , sometimes also called a T.O. package . The schematic symbol for an IC is a triangle or rectangle with the component designator written inside.


IC devices and systems are tiny compared with equivalent circuits made from discrete components. More complex circuits can be built and kept down to a reasonable size using ICs as compared with discrete components. Thus, for example, there are notebook computers with capabilities more advanced than the first computers that were built in the middle 1900s and that took up entire rooms.

High Speed

In an IC, the interconnections among components are physically tiny, making high switching speeds possible. Electric currents travel fast, but not instantaneously. The faster the charge carriers move from one component to another, the more operations can be performed per unit time, and the less time is required for complex tasks.

Low Power Requirement

ICs generally consume less power than equivalent discrete-component circuits. This is important if batteries are used. Because ICs draw so little current, they produce less heat than their discrete-component equivalents. This results in better energy efficiency and minimizes problems that plague equipment that gets hot with use, such as frequency drift and generation of internal noise.


Systems using ICs fail less often per component-hour of use than systems that make use of discrete components. This is so mainly because all interconnections are sealed within an IC case, preventing corrosion or the intrusion of dust. The reduced failure rate translates into less downtime.

IC technology lowers service costs because repair procedures are simple when failures occur. Many systems use sockets for ICs, and replacement is simply a matter of finding the faulty IC, unplugging it, and plugging in a new one. Special desoldering equipment is used for servicing circuit boards that have ICs soldered directly to the foil.

Modular Construction

Modern IC appliances employ modular construction . Individual ICs perform defined functions within a circuit board; the circuit board or card, in turn, fits into a socket and has a specific purpose. Computers programmed with customized software are used by technicians to locate the faulty card in a system. The card can be pulled and replaced, getting the system back to the user in the shortest possible time.

Practice problems of these concepts can be found at: Semiconductors Practice Test

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