Iroegbu Chibuisi received his B.Eng. degree in Electrical and Electronics Engineering from Michael Okpara University of Agriculture, (MOUAU) Umudike, Abia State Nigeria in 2010, and currently a Master of Engineering scholar in the department of Electronics and Communication Engineering, Michael Okpara University of Agriculture, (MOUAU) Umudike, Abia State Nigeria. He is a member of International Association of Engineers. His research interests are in the fields of wireless sensor networks, Electronic and Communication Systems design, Security system design, Expert systems and Artificial Intelligence, Design of Microcontroller based systems,
Because of this elevated focus on the digital domain, basic electrical engi- neering education must change in two ways: First, the traditional approach to teaching circuits and electronics without regard to the digital domain must be replaced by one that stresses the circuits foundations common to both the digital and analog domains. Because most of the fundamental concepts in cir- cuits and electronics are equally applicable to both the digital and the analog domains, this means that, primarily, we must change the way in which we motivate circuits and electronics to emphasize their broader impact on digital systems. For example, although the traditional way of discussing the dynam- ics of first-order RC circuits appears unmotivated to the student headed into digital systems, the same pedagogy is exciting when motivated by the switching behavior of a switch and resistor inverter driving a non-ideal capacitive wire. Similarly, we motivate the study of the step response of a second-order RLC circuit by observing the behavior of a MOS inverter when pin parasitics are included.
Now that a complete circuit has been introduced and examined in detail, we can begin the application of computer methods. As men- tioned in Chapter 1, three software packages will be introduced to demonstrate the options available with each and the differences that exist. All have a broad range of support in the educational and industrial communities. The student version of PSpice (OrCAD Release 9.2 from Cadence Design Systems) will receive the most attention, followed by Electronics Workbench from Multisim and then a few sample programs using a programming language called C . Each approach has its own characteristics with procedures that must be followed exactly; other- wise, error messages will appear. Do not assume that you can “force” the system to respond the way you would prefer—every step is well defined, and one error on the input side can result in results of a mean- ingless nature. At times you may believe that the system is in error because you are absolutely sure you followed every step correctly. In such cases, accept the fact that something was entered incorrectly, and review all your work very carefully. All it takes is a comma instead of a period or a decimal point to generate incorrect results.
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 electrical solution turned out to be more cost effective. Early digital electronics systems were based on magnetically controlled switches (or relays). They were mainly used in the implementation of very simple logic networks. Examples of such are train safety systems, where they are still being used at present. The age of digital electronic computing only started in full with the introduction of the vacuum tube. While originally used almost exclusively for analog processing, it was realized early on that the vacuum tube was useful for digital computations as well. Soon complete computers were realized. The era of the vacuum tube based computer culminated in the design of machines such as the ENIAC (intended for computing artillery firing tables) and the UNIVAC I (the first successful commercial computer). To get an idea about integration density, the ENIAC was 80 feet long, 8.5 feet high and several feet wide and incorporated 18,000 vacuum tubes. It became rapidly clear, however, that this design technology had reached its limits. Reliability problems and excessive power consumption made the implementation of larger engines economically and practically infeasible.