FIGURE 3.3 Sine wave. FIGURE 3.4 Amplitude modulation. FIGURE 3.5 Frequency modulation. FIGURE 3.6 Square wave. Amplitude t = time T = Time = Period f = frequency = 1 / T Peak to Peak Amplitude Amplitude t = time Amplitude t = time Amplitude t = time T = Time = Period ©2002 CRC Press LLC FIGURE 3.3 Sine wave. FIGURE 3.4 Amplitude modulation. FIGURE 3.5 Frequency modulation. FIGURE 3.6 Square wave. Amplitude t = time T = Time = Period f = frequency = 1 / T Peak to Peak Amplitude Amplitude t = time Amplitude t = time Amplitude t = time T = Time = Period ©2002 CRC Press LLC 4 Microprocessor-Based Controllers and Microelectronics 4.1 Introduction to Microelectronics 4.2 Digital Logic 4.3 Overview of Control Computers 4.4 Microprocessors and Microcontrollers 4.5 Programmable Logic Controllers 4.6 Digital Communications 4.1 Introduction to Microelectronics The field of microelectronics has changed dramatically during the last two decades and digital technology has governed most of the application fields in electronics. The design of digital systems is supported by thousands of different integrated circuits supplied by many manufacturers across the world. This makes both the design and the production of electronic products much easier and cost effective. The permanent growth of integrated circuit speed, scale of integration, and reduction of costs have resulted in digital circuits being used instead of classical analog solutions of controllers, filters, and (de)modulators. The growth in computational power can be demonstrated with the following example. One single- chip microcontroller has the computational power equal to that of one 1992 vintage computer notebook. This single-chip microcontroller has the computational power equal to four 1981 vintage IBM personal computers, or to two 1972 vintage IBM 370 mainframe computers. Digital integrated circuits are designed to be universal and are produced in large numbers. Modern integrated circuits have many upgraded features from earlier designs, which allow for “user-friendlier” access and control. As the parameters of Integrated circuits (ICs) influence not only the individually designed IC, but all the circuits that must cooperate with it, a roadmap of the future development of IC technology is updated every year. From this roadmap we can estimate future parameters of the ICs, and adapt our designs to future demands. The relative growth of the number of integrated transistors on a chip is relatively stable. In the case of memory elements, it is equal to approximately 1.5 times the current amount. In the case of other digital ICs, it is equal to approximately 1.35 times the current amount. In digital electronics, we use quantities called logical values instead of the analog quantities of voltage and current. Logical variables usually correspond to the voltage of the signal, but they have only two values: log.1 and log.0. If a digital circuit processes a logical variable, a correct value is recognized because between the logical value voltages there is a gap (see Fig. 4.1). We can arbitrarily improve the resolution of signals by simply using more bits. Ondrej Novak Technical University Liberec Ivan Dolezal Technical University Liberec ©2002 CRC Press LLC 5 An Introduction to Micro- and Nanotechnology 5.1 Introduction The Physics of Scaling • General Mechanisms of Electromechanical Transduction • Sensor and Actuator Transduction Characteristics 5.2 Microactuators Electrostatic Actuation • Electromagnetic Actuation 5.3 Microsensors Strain • Pressure • Acceleration • Force • Angular Rate Sensing (Gyroscopes) 5.4 Nanomachines 5.1 Introduction Originally arising from the development of processes for fabricating microelectronics, micro-scale devices are typically classified according not only to their dimensional scale, but their composition and manu- facture. Nanotechnology is generally considered as ranging from the smallest of these micro-scale devices down to the assembly of individual molecules to form molecular devices. These two distinct yet over- lapping fields of microelectromechanical systems (MEMS) and nanosystems or nanotechnology share a common set of engineering design considerations unique from other more typical engineering systems. Two major factors distinguish the existence, effectiveness, and development of micro-scale and nano- scale transducers from those of conventional scale. The first is the physics of scaling and the second is the suitability of manufacturing techniques and processes. The former is governed by the laws of physics and is thus a fundamental factor, while the latter is related to the development of manufacturing technology, which is a significant, though not fundamental, factor. Due to the combination of these factors, effective micro-scale transducers can often not be constructed as geometrically scaled-down versions of conventional-scale transducers. The Physics of Scaling The dominant forces that influence micro-scale devices are different from those that influence their conventional-scale counterparts. This is because the size of a physical system bears a significant influence on the physical phenomena that dictate the dynamic behavior of that system. For example, larger-scale systems are influenced by inertial effects to a much greater extent than smaller-scale systems, while smaller systems are influenced more by surface effects. As an example, consider small insects that can stand on the surface of still water, supported only by surface tension. The same surface tension is present when Michael Goldfarb Vanderbilt University Alvin Strauss Vanderbilt University Eric J. Barth Vanderbilt University ©2002 CRC Press LLC . time T = Time = Period f = frequency = 1 / T Peak to Peak Amplitude Amplitude t = time Amplitude t = time Amplitude t = time T = Time = Period 20 02 CRC Press LLC FIGURE 3.3 Sine wave. . time T = Time = Period f = frequency = 1 / T Peak to Peak Amplitude Amplitude t = time Amplitude t = time Amplitude t = time T = Time = Period 20 02 CRC Press LLC 4 Microprocessor-Based Controllers. equal to that of one 19 92 vintage computer notebook. This single-chip microcontroller has the computational power equal to four 19 81 vintage IBM personal computers, or to two 19 72 vintage IBM 370