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Transistor Array
Transistor arrays consist of two or more transistors on a common substrate. Unlike more highly integrated circuits, the transistors can be used individually like discrete transistors. That is, the transistors in the array are not connected to each other to implement a specific function. Transistor arrays can consist of bipolar junction transistors or field-effect transistors. There are three main motivations for combining several transistors on one chip and in one package: * to save circuit board space and to reduce the board production cost (only one component needs to be populated instead of several) * to ensure closely matching parameters between the transistors (which is almost guaranteed when the transistors on one chip are manufactured simultaneously and subject to identical manufacturing process variations) * to ensure a closely matching thermal drift of parameters between the transistors (which is achieved by having the transistors in extremely close proximity) The mat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Bruns Monocord-6020 - Controller Board - VEB Halbleiterwerk Frankfurt B342D-0111
Bruns is a surname, and may refer to: * Dmitri Bruns (1929–2020), Estonian architect and architecture theorist * Franklin Richard Bruns Jr. (1912–1979), of Maryland * George Bruns (1914–1983), American music composer * Karl Bruns (fl. 1950s), a retired West German slalom canoeist * Ludwig Bruns (1858–1916), German neurologist * Maddux Bruns (born c. 2003), American baseball player * Manfred Bruns (born 1934), German gay civil rights activist * Neville Bruns (born 1958), Australian rules footballer * Paul von Bruns (1846–1916), German surgeon, son of Victor * Phil Bruns (1931–2012), American television actor * Roger Bruns (born 1941), American author and the former deputy director for the National Archives and Records Administration of the United States. * Thomas Bruns (born 1992), Dutch football player * Thomas Bruns (poet) (born 1976), German writer and poet * Victor Bruns (1904–1996), German composer and bassoonist * Victor von Bruns (1812–1883), German surgeon, f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Differential Amplifier
A differential amplifier is a type of electronic amplifier that amplifies the difference between two input voltages but suppresses any voltage common to the two inputs. It is an analog circuit with two inputs V_\text^- and V_\text^+ and one output V_\text, in which the output is ideally proportional to the difference between the two voltages: : V_\text = A(V_\text^+ - V_\text^-), where A is the gain of the amplifier. Single amplifiers are usually implemented by either adding the appropriate feedback resistors to a standard op-amp, or with a dedicated integrated circuit containing internal feedback resistors. It is also a common sub-component of larger integrated circuits handling analog signals. Theory The output of an ideal differential amplifier is given by : V_\text = A_\text(V_\text^+ - V_\text^-), where V_\text^+ and V_\text^- are the input voltages, and A_\text is the differential gain. In practice, however, the gain is not quite equal for the two inputs. This means, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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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 transistor, resistor, capacitor or other component on an IC with semiconductor material which is doped using an opposite species of the substrate dopant, and connecting this surrounding material to a voltage which reverse-biases the p–n junction that forms, it is possible to create a region which forms an electrically isolated "well" around the component. Operation Assume that the semiconductor wafer is p-type material. Also assume a ring of n-type material is placed around a transistor, and placed beneath the transistor. If the p-type material within the n-type ring is now connected to the negative terminal of the power supply and the n-type ring is connected to the positive terminal, the ' holes' in the p-type region are pulled away from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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ULN2003A
The ULN2003A is an integrated circuit produced by Texas Instruments. It consists of an array of seven NPN Darlington transistors capable of 500 mA, 50 V output. It features common-cathode flyback diodes for switching inductive loads (such as servomotors). It can come in PDIP, SOIC, SOP or TSSOP packaging. In the same family are ULN2002A, ULN2004A, as well as ULQ2003A and ULQ2004A, designed for different logic input levels. The ULN2003A is also similar to the ULN2001A (4 inputs) and the ULN2801A, ULN2802A, ULN2803A, ULN2804A and ULN2805A, only differing in logic input levels ( TTL, CMOS, PMOS) and number of in/outputs (4/7/8). Darlington Transistor A Darlington transistor (also known as Darlington pair) achieves very high current amplification by connecting two bipolar transistors in direct DC coupling so the current amplified by the first transistor is amplified further by the second one. The resultant current gain is the product of those of the two component tran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Flyback Diode
A flyback diode is any diode connected across an inductor used to eliminate flyback, which is the sudden voltage spike seen across an inductive load when its supply current is suddenly reduced or interrupted. It is used in circuits in which inductive loads are controlled by switches, and in switching power supplies and inverters. This diode is known by many other names, such as snubber diode, commutating diode, freewheeling diode, suppressor diode, clamp diode, or catch diode. Operation Fig. 1 shows an inductor connected to a battery - a constant voltage source. The resistor represents the small residual resistance of the inductor's wire windings. When the switch is closed, the voltage from the battery is applied to the inductor, causing current from the battery's positive terminal to flow down through the inductor and resistor. The increase in current causes a back EMF (voltage) across the inductor due to Faraday's law of induction which opposes the change in current. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Darlington Transistor
In electronics, a multi-transistor configuration called the Darlington configuration (commonly called a Darlington pair) is a circuit consisting of two bipolar transistors with the emitter of one transistor connected to the base of the other, such that the current amplified by the first transistor is amplified further by the second one. The collectors of both transistors are connected together. This configuration has a much higher current gain than each transistor taken separately. It acts like and is often packaged as a single transistor. It was invented in 1953 by Sidney Darlington. Behavior A Darlington pair behaves like a single transistor, meaning it has one base, collector, and emitter. It typically creates a high current gain (approximately the product of the gains of the two transistors, due to the fact that their β values multiply together). A general relation between the compound current gain and the individual gains is given by: :\beta_\mathrm = \beta_1 \cdot \b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Log Amplifier
A log amplifier, also known as logarithmic amplifier or logarithm amplifier or log amp, is an amplifier for which the output voltage ''V''out is ''K'' times the natural log of the input voltage ''V''in. This can be expressed as, :V_\text = K \ln\left(\frac\right) where ''V''ref is the normalization constant in volts and ''K'' is the scale factor. The log amplifier gives an output voltage which is proportional to the logarithm of the applied input voltage. To design a log amplifier circuit, high performance op-amps like LM1458, LM771, LM714 are commonly used and a compensated log amplifier may include more than one. In some situations, especially in RF domain, monolithic log amplifiers are also used to reduce number of components and space used, as well improve bandwidth and noise performance. The log amplifier's operation can be inverted by an ''exponentiator'', such as an op-amp configured for exponential output. Log amplifier applications Log amplifiers are used in many wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Current Mirror
A current mirror is a circuit designed to copy a current through one active device by controlling the current in another active device of a circuit, keeping the output current constant regardless of loading. The current being "copied" can be, and sometimes is, a varying signal current. Conceptually, an ideal current mirror is simply an ideal ''inverting current amplifier'' that reverses the current direction as well. Or it can consist of a current-controlled current source (CCCS). The current mirror is used to provide bias currents and active loads to circuits. It can also be used to model a more realistic current source (since ideal current sources don't exist). The circuit topology covered here is one that appears in many monolithic ICs. It is a Widlar mirror without an emitter degeneration resistor in the follower (output) transistor. This topology can only be done in an IC, as the matching has to be extremely close and cannot be achieved with discretes. Another topology i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Analogue Circuit
Analogue electronics ( en-US, analog electronics) are electronic systems with a continuously variable signal, in contrast to digital electronics where signals usually take only two levels. The term "analogue" describes the proportional relationship between a signal and a voltage or current that represents the signal. The word analogue is derived from the el, word ανάλογος (analogos) meaning "proportional". Analogue signals An analogue signal uses some attribute of the medium to convey the signal's information. For example, an aneroid barometer uses the angular position of a needle as the signal to convey the information of changes in atmospheric pressure. Electrical signals may represent information by changing their voltage, current, frequency, or total charge. Information is converted from some other physical form (such as sound, light, temperature, pressure, position) to an electrical signal by a transducer which converts one type of energy into another (e.g. a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Circuit Board
A printed circuit board (PCB; also printed wiring board or PWB) is a medium used in electrical and electronic engineering to connect electronic components to one another in a controlled manner. It takes the form of a laminated sandwich structure of conductive and insulating layers: each of the conductive layers is designed with an artwork pattern of traces, planes and other features (similar to wires on a flat surface) etched from one or more sheet layers of copper laminated onto and/or between sheet layers of a non-conductive substrate. Electrical components may be fixed to conductive pads on the outer layers in the shape designed to accept the component's terminals, generally by means of soldering, to both electrically connect and mechanically fasten them to it. Another manufacturing process adds vias: plated-through holes that allow interconnections between layers. Printed circuit boards are used in nearly all electronic products. Alternatives to PCBs include wire w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Field-effect Transistor
The field-effect transistor (FET) is a type of transistor that uses an electric field to control the flow of current in a semiconductor. FETs ( JFETs or MOSFETs) are devices with three terminals: ''source'', ''gate'', and ''drain''. FETs control the flow of current by the application of a voltage to the gate, which in turn alters the conductivity between the drain and source. FETs are also known as unipolar transistors since they involve single-carrier-type operation. That is, FETs use either electrons (n-channel) or holes (p-channel) as charge carriers in their operation, but not both. Many different types of field effect transistors exist. Field effect transistors generally display very high input impedance at low frequencies. The most widely used field-effect transistor is the MOSFET (metal-oxide-semiconductor field-effect transistor). History The concept of a field-effect transistor (FET) was first patented by Austro-Hungarian physicist Julius Edgar Lilienfeld in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |