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Miller Effect
In electronics, the Miller effect (named after its discoverer John Milton Miller) accounts for the increase in the equivalent input capacitance of an inverting voltage amplifier due to amplification of the effect of capacitance between the amplifier's input and output terminals, and is given by :C_=C (1+A_v)\, where -A_v is the voltage gain of the inverting amplifier (A_v positive) and C is the feedback capacitance. Although the term ''Miller effect'' normally refers to capacitance, any impedance connected between the input and another node exhibiting gain can modify the amplifier input impedance via this effect. These properties of the Miller effect are generalized in the Miller theorem. The Miller capacitance due to undesired parasitic capacitance between the output and input of active devices like transistors and vacuum tubes is a major factor limiting their gain at high frequencies. History When Miller published his work in 1919, he was working on vacuum tube triodes. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronics
Electronics is a scientific and engineering discipline that studies and applies the principles of physics to design, create, and operate devices that manipulate electrons and other Electric charge, electrically charged particles. It is a subfield of physics and electrical engineering which uses Passivity (engineering), active devices such as transistors, diodes, and integrated circuits to control and amplify the flow of electric current and to convert it from one form to another, such as from alternating current (AC) to direct current (DC) or from analog signal, analog signals to digital signal, digital signals. Electronic devices have significantly influenced the development of many aspects of modern society, such as telecommunications, entertainment, education, health care, industry, and security. The main driving force behind the advancement of electronics is the semiconductor industry, which continually produces ever-more sophisticated electronic devices and circuits in respo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RC Time Constant
The RC time constant, denoted ' (lowercase tau), the time constant of a resistor–capacitor circuit (RC circuit), is equal to the product of the circuit resistance and the circuit capacitance: : \tau = RC \, . It is the time required to charge the capacitor, through the resistor, from an initial charge voltage of zero to approximately 63.2% of the value of an applied DC voltage, or to discharge the capacitor through the same resistor to approximately 36.8% of its initial charge voltage. These values are derived from the mathematical constant '' e'', where 63.2\% \approx 1e^ and 36.8\% \approx e^. When using the International System of Units, is in ohms, is in farads, and is in seconds. Discharging a capacitor through a series resistor to zero volts from an initial voltage of results in the capacitor having the following exponentially-decaying voltage curve: :V_\text(t) = V_0 \cdot (e^) Charging an uncharged capacitor through a series resistor to an applied consta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low-pass Filter
A low-pass filter is a filter that passes signals with a frequency lower than a selected cutoff frequency and attenuates signals with frequencies higher than the cutoff frequency. The exact frequency response of the filter depends on the filter design. The filter is sometimes called a high-cut filter, or treble-cut filter in audio applications. A low-pass filter is the complement of a high-pass filter. In optics, high-pass and low-pass may have different meanings, depending on whether referring to the frequency or wavelength of light, since these variables are inversely related. High-pass frequency filters would act as low-pass wavelength filters, and vice versa. For this reason, it is a good practice to refer to wavelength filters as ''short-pass'' and ''long-pass'' to avoid confusion, which would correspond to ''high-pass'' and ''low-pass'' frequencies. Low-pass filters exist in many different forms, including electronic circuits such as a '' hiss filter'' used in audio, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Source
In electronics, a common-source amplifier is one of three basic single-stage field-effect transistor (FET) amplifier topologies, typically used as a voltage or transconductance amplifier. The easiest way to tell if a FET is common source, common drain, or common gate is to examine where the signal enters and leaves. The remaining terminal is what is known as "common". In this example, the signal enters the gate, and exits the drain. The only terminal remaining is the source. This is a common-source FET circuit. The analogous bipolar junction transistor circuit may be viewed as a transconductance amplifier or as a voltage amplifier. (See classification of amplifiers). As a transconductance amplifier, the input voltage is seen as modulating the current going to the load. As a voltage amplifier, input voltage modulates the current flowing through the FET, changing the voltage across the output resistance according to Ohm's law. However, the FET device's output resistance typica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Derivation
Derivation may refer to: Language * Morphological derivation, a word-formation process * Parse tree or concrete syntax tree, representing a string's syntax in formal grammars Law * Derivative work, in copyright law * Derivation proceeding, a proceeding in United States patent law Music * The creation of a derived row, in the twelve-tone musical technique Science and mathematics * Derivation (differential algebra), a unary function satisfying the Leibniz product law * Formal proof or derivation, a sequence of sentences each of which is an axiom or follows from the preceding sentences in the sequence by a rule of inference * An after-the-fact justification for an action, in the work of sociologist Vilfredo Pareto See also * Derive (other), for meanings of "derive" and "derived" * Derivative, in calculus * Derivative (other) * {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thévenin's Theorem
As originally stated in terms of direct-current resistance (electricity), resistive circuits only, Thévenin's theorem states that ''"Any linear circuit, linear electrical network containing only voltage source, voltage sources, current source, current sources and resistance (electricity), resistances can be replaced at terminals by an equivalent combination of a voltage source in a series and parallel circuit, series connection with a resistance ."'' * The equivalent voltage is the voltage obtained at terminals of the network with terminals open-circuit voltage, open circuited. * The equivalent resistance is the resistance that the circuit between terminals and would have if all ideal voltage sources in the circuit were replaced by a short circuit and all ideal current sources were replaced by an open circuit (i.e., the sources are set to provide zero voltages and currents). * If terminals and are connected to one another (short), then the current flowing from and wil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miller Effect Illustration 1
A miller is a person who operates a mill, a machine to grind a grain (for example corn or wheat) to make flour. Milling is among the oldest of human occupations. "Miller", "Milne" and other variants are common surnames, as are their equivalents in other languages around the world (" Melnyk" in Russian, Belarusian & Ukrainian, " Meunier" in French, "Müller" or " Mueller" in German, " Mulder" and " Molenaar" in Dutch, "Molnár" in Hungarian, " Molinero" in Spanish, "Molinaro" or "Molinari" in Italian, "Mlinar" in South Slavic languages etc.). Milling existed in hunter-gatherer communities, and later millers were important to the development of agriculture. The materials ground by millers are often foodstuffs and particularly grain. The physical grinding of the food allows for the easier digestion of its nutrients and saves wear on the teeth. Non-food substances needed in a fine, powdered form, such as building materials, may be processed by a miller. Quern-stone The mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutrodyne
The Neutrodyne radio receiver, invented in 1922 by Louis Hazeltine, was a particular type of tuned radio frequency (TRF) receiver, in which the instability-causing inter-electrode capacitance of the triode RF tubes is cancelled out or "neutralized"US Patent No. 1450080, Louis Alan Hazeltine "Method and electric circuit arrangement for neutralizing capacity coupling" filed August 7, 1919; granted March 27, 1923 to prevent parasitic oscillations which caused "squealing" or "howling" noises in the speakers of early radio sets. In most designs, a small extra winding on each of the RF amplifiers' tuned anode coils was used to generate a small antiphase signal, which could be adjusted by special variable trim capacitors to cancel out the stray signal coupled to the grid via plate-to-grid capacitance. The Neutrodyne circuit was popular in radio receivers until the 1930s, when it was superseded by the superheterodyne receiver. History The circuit was developed about 1922 by Haro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cascode
The cascode is a two-stage amplifier that consists of a common emitter stage feeding into a common base stage when using bipolar junction transistors (BJTs) or alternatively a common source stage feeding a common gate stage when using field-effect transistors (FETs). Because there is no direct coupling from the output to input, the Miller effect is eliminated, contributing to a much higher bandwidth. Compared to a single amplifier stage, this combination may have one or more of the following characteristics: higher input–output isolation, higher input impedance, high output impedance, higher bandwidth (signal processing), bandwidth. History The use of a cascode (sometimes verbification, verbified to ''cascoding'') is a common technique for improving analog circuit performance, applicable to both vacuum tubes and transistors. The name "cascode" was coined in an article written by Frederick Vinton Hunt and Roger Wayne Hickman in 1939, in a discussion on the application of ... [...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 inverted; i.e. for a sine wave input signal, the output signal is 180 degrees out of phase with respect to the input. 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 f ... [...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 configurat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integrated Circuits
An integrated circuit (IC), also known as a microchip or simply chip, is a set of electronic circuits, consisting of various electronic components (such as transistors, resistors, and capacitors) and their interconnections. These components are etched onto a small, flat piece ("chip") of semiconductor material, usually silicon. Integrated circuits are used in a wide range of electronic devices, including computers, smartphones, and televisions, to perform various functions such as processing and storing information. They have greatly impacted the field of electronics by enabling device miniaturization and enhanced functionality. Integrated circuits are orders of magnitude smaller, faster, and less expensive than those constructed of discrete components, allowing a large transistor count. The IC's mass production capability, reliability, and building-block approach to integrated circuit design have ensured the rapid adoption of standardized ICs in place of designs using discre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
