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Gummel Plot
In electronics, the Gummel plot is the combined plot of the base and collector electric currents, I_\text and I_\text, of a bipolar transistor vs. the base–emitter voltage, V_\text, on a semi-logarithmic scale. This plot is very useful in device characterization because it reflects on the quality of the emitter–base junction while the base–collector bias, V_\text, is kept constant. A number of other device parameters can be garnered either quantitatively or qualitatively directly from the Gummel plot:A. S. Zoolfakar et N. A. Shahrol, «Modelling of NPN Bipolar Junction Transistor Characteristics Using Gummel Plot Technique», in 2010 International Conference on Intelligent Systems, Modelling and Simulation (ISMS), 2010, p. 396–400. * The common-emitter current gain, \beta, and the common-base current gain, \alpha, * Base and collector ideality factors, n, * Series resistances and leakage currents. Sometimes the DC current gain, \beta, is plotted on the same figure as we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Qualitative Data
Qualitative properties are properties that are observed and can generally not be measured with a numerical result. They are contrasted to quantitative properties which have numerical characteristics. Some engineering and scientific properties are qualitative. A test method can result in qualitative data about something. This can be a categorical result or a binary classification Binary classification is the task of classifying the elements of a set into two groups (each called ''class'') on the basis of a classification rule. Typical binary classification problems include: * Medical testing to determine if a patient has c ... (e.g., pass/fail, go/no go, Conformity, conform/non-conform). It can sometimes be an engineering judgement. The data that all share a qualitative property form a nominal category. A variable which codes for the presence or absence of such a property is called a binary categorical variable, or equivalently a dummy variable (statistics), dummy variable. In b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gummel–Poon Model
The Gummel–Poon model is a model of the bipolar junction transistor. It was first described in an article published by Hermann Gummel and H. C. Poon at Bell Labs in 1970.H. K. Gummel and H. C. Poon, "An integral charge control model of bipolar transistors", ''Bell Syst. Tech. J.'', vol. 49, pp. 827–852, May–June 1970. The Gummel–Poon model and modern variants of it are widely used in the popular circuit simulators such as SPICE. A significant effect that the Gummel–Poon model accounts for is the variation of the transistor \beta_\text and \beta_\text values with the direct current Direct current (DC) is one-directional flow of electric charge. An electrochemical cell is a prime example of DC power. Direct current may flow through a conductor such as a wire, but can also flow through semiconductors, insulators, or eve ... level. When certain parameters are omitted, the Gummel–Poon model reduces to the simpler Ebers–Moll model. Model parameters Spice Gumme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hermann Gummel
Hermann K. Gummel (5 July 1923 – 5 September 2022) was a German physicist and pioneer in the semiconductor industry. Gummel received his '' Diplom'' degree in physics from Philipps University (Marburg, Germany) in 1952. He received his M.S. (1952) and Ph.D. (1957) degrees in theoretical semiconductor physics from Syracuse University. Gummel joined Bell Laboratories in 1956; his doctoral advisor, Melvin Lax, had moved from Syracuse University to Bell the previous year. At Bell, Gummel made important contributions to the design and simulation of the semiconductor devices used throughout modern electronics. Among the most important of his contributions are the Gummel–Poon model which made accurate simulation of bipolar transistors possible and which was central to the development of the SPICE program; Gummel's method, used to solve the equations for the detailed behavior of individual bipolar transistors,; and the Gummel plot, used to characterize bipolar transistors. Gumme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leakage Current
In electronics, leakage is the gradual transfer of electrical energy across a boundary normally viewed as insulating, such as the spontaneous discharge of a charged capacitor, magnetic coupling of a transformer with other components, or flow of current across a transistor in the "off" state or a reverse-polarized diode. In capacitors Gradual loss of energy from a charged capacitor is primarily caused by electronic devices attached to the capacitors, such as transistors or diodes, which conduct a small amount of current even when they are turned off. Even though this off current is an order of magnitude less than the current through the device when it is on, the current still slowly discharges the capacitor. Another contributor to leakage from a capacitor is from the undesired imperfection of some dielectric materials used in capacitors, also known as ''dielectric leakage''. It is a result of the dielectric material not being a perfect insulator and having some non-zero conductivit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Resistance
The electrical resistance of an object is a measure of its opposition to the flow of electric current. Its reciprocal quantity is , measuring the ease with which an electric current passes. Electrical resistance shares some conceptual parallels with mechanical friction. The SI unit of electrical resistance is the ohm (), while electrical conductance is measured in siemens (S) (formerly called the 'mho' and then represented by ). The resistance of an object depends in large part on the material it is made of. Objects made of electrical insulators like rubber tend to have very high resistance and low conductance, while objects made of electrical conductors like metals tend to have very low resistance and high conductance. This relationship is quantified by resistivity or conductivity. The nature of a material is not the only factor in resistance and conductance, however; it also depends on the size and shape of an object because these properties are extensive rather than intens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common-base
In electronics, a common-base (also known as grounded-base) electronic amplifier, amplifier is one of three basic single-stage bipolar junction transistor (BJT) amplifier topologies, typically used as a current buffer or voltage amplifier. In this circuit the emitter terminal of the transistor serves as the input, the collector as the output, and the base is connected to ground, or "common", hence its name. The analogous field-effect transistor circuit is the common-gate amplifier. Applications This arrangement is not very common in low-frequency discrete circuits, where it is usually employed for amplifiers that require an unusually low input impedance, for example to act as a preamplifier for moving-coil microphones. However, it is popular in integrated circuits and in high-frequency amplifiers, for example for VHF and Ultra high frequency, UHF, because its input capacitance does not suffer from the Miller effect, which degrades the bandwidth of the common-emitter configurati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common-emitter
In electronics, a common-emitter amplifier is one of three basic single-stage bipolar-junction-transistor (BJT) amplifier topologies, typically used as a voltage amplifier. It offers high current gain (typically 200), medium input resistance and a high output resistance. The output of a common emitter amplifier is 180 degrees out of phase to the input signal. In this circuit the base terminal of the transistor serves as the input, the collector is the output, and the emitter is ''common'' to both (for example, it may be tied to ground reference or a power supply rail), hence its name. The analogous FET circuit is the common-source amplifier, and the analogous tube circuit is the common-cathode amplifier. Emitter degeneration Common-emitter amplifiers give the amplifier an inverted output and can have a very high gain that may vary widely from one transistor to the next. The gain is a strong function of both temperature and bias current, and so the actual gain is somewhat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantitative Property
Quantitative research is a research strategy that focuses on quantifying the collection and analysis of data. It is formed from a deductive approach where emphasis is placed on the testing of theory, shaped by empiricist and positivist philosophies. Associated with the natural, applied, formal, and social sciences this research strategy promotes the objective empirical investigation of observable phenomena to test and understand relationships. This is done through a range of quantifying methods and techniques, reflecting on its broad utilization as a research strategy across differing academic disciplines. The objective of quantitative research is to develop and employ mathematical models, theories, and hypotheses pertaining to phenomena. The process of measurement is central to quantitative research because it provides the fundamental connection between empirical observation and mathematical expression of quantitative relationships. Quantitative data is any data that is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronics
The field of electronics is a branch of physics and electrical engineering that deals with the emission, behaviour and effects of electrons using electronic devices. Electronics uses active devices to control electron flow by amplification and rectification, which distinguishes it from classical electrical engineering, which only uses passive effects such as resistance, capacitance and inductance to control electric current flow. Electronics has hugely influenced the development of modern society. The central driving force behind the entire electronics industry is the semiconductor industry sector, which has annual sales of over $481 billion as of 2018. The largest industry sector is e-commerce, which generated over $29 trillion in 2017. History and development Electronics has hugely influenced the development of modern society. The identification of the electron in 1897, along with the subsequent invention of the vacuum tube which could amplify and rectify small ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constant (mathematics)
In mathematics, the word constant conveys multiple meanings. As an adjective, it refers to non-variance (i.e. unchanging with respect to some other value); as a noun, it has two different meanings: * A fixed and well-defined number or other non-changing mathematical object. The terms '' mathematical constant'' or '' physical constant'' are sometimes used to distinguish this meaning. * A function whose value remains unchanged (i.e., a constant function). Such a constant is commonly represented by a variable which does not depend on the main variable(s) in question. For example, a general quadratic function is commonly written as: :a x^2 + b x + c\, , where , and are constants (or parameters), and a variable—a placeholder for the argument of the function being studied. A more explicit way to denote this function is :x\mapsto a x^2 + b x + c \, , which makes the function-argument status of (and by extension the constancy of , and ) clear. In this example , and are co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Junction (semiconductor)
{{Unreferenced, date=June 2019, bot=noref (GreenC bot) An electrical junction is a point or area where multiple conductors or semiconductors make physical contact. Electrical junctions types include thermoelectricity junctions, metal–semiconductor junctions and p–n junctions. Junctions are either rectifying or non-rectifying. Non-rectifying junctions are called ohmic contacts. Electronic components employing rectifying junctions include p–n diodes, Schottky diodes and bipolar junction transistors. (Electrical outlets ) See also * Break junction * Depletion region, also called junction region ** Junction voltage * Heterojunction * Homojunction * Josephson junction * Nodal analysis * p–n junction isolation p–n junction isolation is a method used to electrically isolate electronic components, such as transistors, on an integrated circuit (IC) by surrounding the components with reverse biased p–n junctions. Introduction By surrounding a transis ... Electricity ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
