Linear versus digital

Chapter Linear versus digital

Teach Yourself Electricity and Electronics Third Edition Book
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Summary of Contents

Teach Yourself Electricity and Electronics Third Edition Book

  • High power necessitates a certain minimum physical bulk, because such amplifiers alwaysgenerate large amounts of heat.This isn’t a serious drawback. Power transistors and vacuum tubes are available toperform high-power tasks. Integrated circuits are no different than anything else:they’re good at some things, and not so good at others.Linear versus digitalA linear IC is used to process analog signals such as voices, music, and radio transmis-sions. The term “linear” arises from the fact that, in general, the amplification factor isconstant as the input amplitude varies. That is, the output signal strength is a linearfunction of the input signal strength (Fig. 28-2).524 Integrated circuits and data storage media28-2Relative output versusinput in a linear IC.A digital IC, also sometimes called a digital-logic IC, operates using just twostates, called high and low. These are sometimes called logic 1 and logic 0, respec-tively. Digital logic is discussed in detail in chapter 30. Digital ICs consist of many logicgates that perform operations in binary algebra. Several different digital IC technolo-gies exist; these are briefly outlined later in this chapter.Types of linear ICsThere are numerous situations in which linear integrated circuits can be used. LinearICs include amplifiers, regulators, timers, multiplexers, and comparators.The operational amplifierAn operational amplifier, or op amp, is a specialized form of linear IC. The op ampconsists of several transistors, resistors, diodes, and capacitors, interconnected so thathigh gain is possible over a wide range of frequencies. An op amp might comprise an en-tire IC. Or, an IC might consist of two or more op amps. Thus, you’ll sometimes hear ofdual op amps or quad op amps. Some ICs have op amps in addition to various othercircuits.An op amp has two inputs, one noninverting and one inverting, and one output. Whena signal goes into the noninverting input, the output is in phase with it; when a signal goes