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Analog Chip
A linear integrated circuit or analog chip is a set of miniature electronic analog circuits formed on a single piece of semiconductor material. Description The voltage and current at specified points in the circuits of analog chips vary continuously over time. In contrast, digital chips only assign meaning to voltages or currents at discrete levels. In addition to transistors, analog chips often include a larger number of passive elements (capacitors, resistors, and inductors) than digital chips. Inductors tend to be avoided because of their large physical size, and difficulties incorporating them into monolithic semiconductor ICs. Certain circuits such as gyrators can often act as equivalents of inductors, while constructed only from transistors and capacitors. Analog chips may also contain digital logic elements to replace some analog functions, or to allow the chip to communicate with a microprocessor. For this reason, and since logic is commonly implemented using CMOS techno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Analog 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. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operational Amplifier
An operational amplifier (often op amp or opamp) is a DC-coupled high-gain electronic voltage amplifier with a differential input and, usually, a single-ended output. In this configuration, an op amp produces an output potential (relative to circuit ground) that is typically 100,000 times larger than the potential difference between its input terminals. The operational amplifier traces its origin and name to analog computers, where they were used to perform mathematical operations in linear, non-linear, and frequency-dependent circuits. The popularity of the op amp as a building block in analog circuits is due to its versatility. By using negative feedback, the characteristics of an op-amp circuit, its gain, input and output impedance, bandwidth etc. are determined by external components and have little dependence on temperature coefficients or engineering tolerance in the op amp itself. Op amps are used widely in electronic devices today, including a vast array of consumer, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precision Monolithics
Precision Monolithics, Inc. also known as PMI, was an American company based in Santa Clara, California, that developed and produced mixed signal and linear integrated circuits (ICs). It was a pioneer in the fields of digital-to-analog converters and operational amplifiers. The company was founded in 1969 by Marv Rudin and Garth Wilson, who had both left Fairchild Semiconductor at the end of 1968. Wilson was circuit design manager under Rudin, who managed linear circuit R&D at the Fairchild Semiconductor R&D Laboratory in Palo Alto from 1966 to 1968. At the beginning, Wilson was vice president responsible for engineering and production, and reported to Rudin, who was president and marketing manager. Jim Grugan from Fairchild joined shortly after incorporation as vice president of administration, responsible for finance, facilities and purchasing. Immediately after financing and incorporation, they offered founder stock and hired IC designers George Erdi from Fairchild and Dan Doo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hans Camenzind
Hans R. Camenzind (; 1 January 1934 – 8 August 2012) was an electronics engineer known for designing the 555 timer IC in 1971 under contract to Signetics. He was the inventor on 20 United States patent law, US patents. Camenzind also wrote three books and numerous technical articles, and lectured at the Santa Clara University, University of Santa Clara. Background and education Camenzind was born and raised in Zürich, Switzerland, where he went to college. In 1960 he moved to the United States, first receiving an MSEE from Northeastern University and then an MBA from the University of Santa Clara. Camenzind taught circuit design in the morning, then attending classes at the same university at night working towards a Master's degree in Business Administration. Career In 1962, Camenzind joined the Laboratory for Physical Science at P. R. Mallory and Co Inc, P.R. Mallory in Burlington, Massachusetts. After six years of research, Camenzind moved to California in 1968 to join S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bob Pease
Robert Allen Pease (August 22, 1940 – June 18, 2011) was an electronics engineer known for analog integrated circuit (IC) design, and as the author of technical books and articles about electronic design. He designed several very successful "best-seller" ICs, many of them in continuous production for multiple decades.These include LM331 voltage-to-frequency converter, and the LM337 adjustable negative voltage regulator (complement to the LM317). Life and career Pease was born on August 22, 1940 in Rockville, Connecticut. He attended Northfield Mount Hermon School in Massachusetts, and subsequently obtained a Bachelor of Science in Electrical Engineering (BSEE) degree from Massachusetts Institute of Technology in 1961. He started work in the early 1960s at George A. Philbrick Researches (GAP-R). GAP-R pioneered the first reasonable-cost, mass-produced operational amplifier (op-amp), the K2-W. At GAP-R, Pease developed many high-performance op-amps, built with discrete so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bob Widlar
Robert John Widlar (pronounced ''wide-lar''; November 30, 1937 – February 27, 1991) was an American electronics engineer and a designer of linear integrated circuits (ICs). Early years Widlar was born November 30, 1937 in Cleveland to parents of Czech, Irish and German ethnicity.Lojek, p. 250. His mother, Mary Vithous, was born in Cleveland to Czech immigrants Frank Vithous (František Vitous (or Vitouš?)) and Marie Zakova (Marie Žáková).Lojek, p. 249. His father, Walter J. Widlar, came from prominent German and Irish American families whose ancestors settled in Cleveland in the middle of the 19th century. A self-taught radio engineer, Walter Widlar worked for the radio station and designed pioneering ultra high frequency transmitters. The world of electronics surrounded him since birth: one of his brothers became the first baby monitored by wireless radio. Guided by his father, Bob developed a strong interest in electronics in early childhood. Widlar never talked ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Band Gap
In solid-state physics, a band gap, also called an energy gap, is an energy range in a solid where no electronic states can exist. In graphs of the electronic band structure of solids, the band gap generally refers to the energy difference (in electron volts) between the top of the valence band and the bottom of the conduction band in insulators and semiconductors. It is the energy required to promote a valence electron bound to an atom to become a conduction electron, which is free to move within the crystal lattice and serve as a charge carrier to conduct electric current. It is closely related to the HOMO/LUMO gap in chemistry. If the valence band is completely full and the conduction band is completely empty, then electrons cannot move within the solid because there are no available states. If the electrons are not free to move within the crystal lattice, then there is no generated current due to no net charge carrier mobility. However, if some electrons transfer from th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bandgap Voltage Reference
A bandgap voltage reference is a temperature independent voltage reference circuit widely used in integrated circuits. It produces a fixed (constant) voltage regardless of power supply variations, temperature changes, or circuit loading from a device. It commonly has an output voltage around 1.25V (close to the theoretical band gap of silicon at absolute zero, 0K). This circuit concept was first published by David Hilbiber in 1964. Bob Widlar, Paul Brokaw and others followed up with other commercially successful versions. Operation The voltage difference between two p–n junctions (e.g. diodes), operated at different current densities, is used to generate a current that is ''proportional to absolute temperature'' (''PTAT'') in a resistor. This current is used to generate a voltage in a second resistor. This voltage in turn is added to the voltage of one of the junctions (or a third one, in some implementations). The voltage across a diode operated at constant current is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voltage Reference
A voltage reference is an electronic device that ideally produces a fixed (constant) voltage irrespective of the loading on the device, power supply variations, temperature changes, and the passage of time. Voltage references are used in power supplies, analog-to-digital converters, digital-to-analog converters, and other measurement and control systems. Voltage references vary widely in performance; a regulator for a computer power supply may only hold its value to within a few percent of the nominal value, whereas laboratory voltage standards have precisions and stability measured in parts per million. In metrology The earliest voltage references or standards were wet-chemical cells such as the Clark cell and Weston cell, which are still used in some laboratory and calibration applications. Laboratory-grade Zener diode secondary solid-state voltage standards used in metrology can be constructed with a drift of about 1 part per million per year.Manfred Kochsiek, Michael Gläser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
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 is t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Current Source
A current source is an electronic circuit that delivers or absorbs an electric current which is independent of the voltage across it. A current source is the dual of a voltage source. The term ''current sink'' is sometimes used for sources fed from a negative voltage supply. Figure 1 shows the schematic symbol for an ideal current source driving a resistive load. There are two types. An ''independent current source'' (or sink) delivers a constant current. A ''dependent current source'' delivers a current which is proportional to some other voltage or current in the circuit. Background , - align="center" , style="padding: 1em 2em 0;", , style="padding: 1em 2em 0;", , - align="center" , Voltage source , Current source , - align="center" , style="padding: 1em 2em 0;", , style="padding: 1em 2em 0;", , - align="center" , Controlled voltage source , Controlled current source , - align="center" , style="padding: 1em 2em 0;", , style="padding: 1em 2em 0;", , - align ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
