marketing channel. Digitally enhanced customer service, interactive store displays, rapid fulfillment, printed electronics like smart tags and NFC labels, image recognition technology, mobile apps, new point- of-sale systems, mobile payment systems, application program interfaces (APIs) and advanced customer relationship management analytics are just some of the technologies that will enable marketers to completely reinvent the customer experience of the brand. Recently, Walgreens allowed developers to access its photo printing services through APIs, which led to the creation of applications that allowed users to print photos from Facebook and Instagram. The popularity of these applications enhanced customer engagement and led to a six- fold increase in revenue from these customers.
This book is designed to serve as a first course in an electrical engineering or an electrical engineering and computer science curriculum, providing students at the sophomore level a transition from the world of physics to the world of electronics and computation. The book attempts to satisfy two goals: Combine circuits and electronics into a single, unified treatment, and establish a strong connection with the contemporary worlds of both digital and analog systems. These goals arise from the observation that the approach to introduc- ing electrical engineering through a course in traditional circuit analysis is fast becoming obsolete. Our world has gone digital. A large fraction of the student population in electrical engineering is destined for industry or graduate study in digital electronics or computer systems. Even those students who remain in core electrical engineering are heavily influenced by the digital domain.
Semiconductors have a number of parameters that vary linearly with temperature. Normally the reference voltage of a zener diode or the junction voltage variations are used for temperature sensing. Semiconductor temperature sensors have a lim- ited operating range from –50 to 150 ° C but are very linear with accuracies of ± 1 ° C or better. Other advantages are that electronics can be integrated onto the same die as the sensor giving high sensitivity, easy interfacing to control systems, and making different digital output configurations possible. The thermal time con- stant varies from 1 to 5 s, internal dissipation can also cause up to 0.5 ° C offset. Semiconductor devices are also rugged with good longevity and are inexpensive. For the above reasons the semiconductor sensor is used extensively in many appli- cations including the replacement of the mercury in glass thermometer.
Materials that are utilized in high-technology (or high-tech) applications are some- times termed advanced materials. By high technology we mean a device or product that operates or functions using relatively intricate and sophisticated principles; examples include electronic equipment (VCRs, CD players, etc.), computers, fiber- optic systems, spacecraft, aircraft, and military rocketry. These advanced materials are typically either traditional materials whose properties have been enhanced or newly developed, high-performance materials. Furthermore, they may be of all material types (e.g., metals, ceramics, polymers), and are normally relatively expen- sive. In subsequent chapters are discussed the properties and applications of a number of advanced materials—for example, materials that are used for lasers, integrated circuits, magnetic information storage, liquid crystal displays (LCDs), fiber optics, and the thermal protection system for the Space Shuttle Orbiter.
Before the 1960s, semiconductor engineering was regarded as part of low-current and low-voltage electronic engineering. The currents used in solid-state devices were below one ampere and voltages only a few tens of volts. The year 1970 began one of the most exciting decades in the history of low-current electronics. A number of companies entered the field, including Analog Devices, Computer Labs, and National Semiconductor. The 1980s represented high growth years for integrated circuits, hybrid, and modular data converters. The 1990s major applications were industrial process control, measurement, instrumentation, medicine, audio, video, and computers. In addition, communications became an even bigger driving force for low-cost, low-power, high-performance converters in modems, cell-phone handsets, wireless infrastructure, and other portable applications. The trends of more highly integrated functions and power dissipation drop have continued into the 2000s.
The growing sensitivity to the technologies on Wall Street is clear evi- dence that the electrical/electronics industry is one that will have a sweep- ing impact on future development in a wide range of areas that affect our life style, general health, and capabilities. Even the arts, initially so deter- mined not to utilize technological methods, are embracing some of the new, innovative techniques that permit exploration into areas they never thought possible. The new Windows approach to computer simulation has made computer systems much friendlier to the average person, resulting in an expanding market which further stimulates growth in the field. The computer in the home will eventually be as common as the telephone or television. In fact, all three are now being integrated into a single unit. Every facet of our lives seems touched by developments that appear to surface at an ever-increasing rate. For the layperson, the most obvious improvement of recent years has been the reduced size of electrical/ elec- tronics systems. Televisions are now small enough to be hand-held and have a battery capability that allows them to be more portable. Computers with significant memory capacity are now smaller than this textbook. The size of radios is limited simply by our ability to read the numbers on the face of the dial. Hearing aids are no longer visible, and pacemakers are significantly smaller and more reliable. All the reduction in size is due primarily to a marvelous development of the last few decades—the integrated circuit (IC). First developed in the late 1950s, the IC has now reached a point where cutting 0.18-micrometer lines is commonplace. The integrated circuit shown in Fig. 1.1 is the Intel ® Pentium ® 4 processor, which has 42 million transistors in an area measuring only 0.34 square inches. Intel Corporation recently presented a technical paper describing 0.02-micrometer (20-nanometer) transistors, developed in its silicon research laboratory. These small, ultra-fast transistors will permit placing nearly one billion transistors on a sliver of silicon no larger than a finger- nail. Microprocessors built from these transistors will operate at about 20 GHz. It leaves us only to wonder about the limits of such development. It is natural to wonder what the limits to growth may be when we consider the changes over the last few decades. Rather than following a steady growth curve that would be somewhat predictable, the industry is subject to surges that revolve around significant developments in the field. Present indications are that the level of miniaturization will con- tinue, but at a more moderate pace. Interest has turned toward increas- ing the quality and yield levels (percentage of good integrated circuits in the production process).