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PLL
A phase-locked loop or phase lock loop (PLL) is a control system that generates an output Signal (electrical engineering), signal whose phase (waves), phase is related to the phase of an input signal. There are several different types; the simplest is an electronic circuit consisting of a variable frequency oscillator and a phase detector in a feedback loop. The oscillator's frequency and phase are controlled proportionally by an applied voltage, hence the term voltage-controlled oscillator (VCO). The oscillator generates a periodic signal of a specific frequency, and the phase detector compares the phase of that signal with the phase of the input periodic signal, to adjust the oscillator to keep the phases matched. Keeping the input and output phase in lockstep also implies keeping the input and output frequencies the same. Consequently, in addition to synchronizing signals, a phase-locked loop can track an input frequency, or it can generate a frequency that is a multiple of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phase Locked Loop
A phase-locked loop or phase lock loop (PLL) is a control system that generates an output signal whose phase is related to the phase of an input signal. There are several different types; the simplest is an electronic circuit consisting of a variable frequency oscillator and a phase detector in a feedback loop. The oscillator's frequency and phase are controlled proportionally by an applied voltage, hence the term voltage-controlled oscillator (VCO). The oscillator generates a periodic signal of a specific frequency, and the phase detector compares the phase of that signal with the phase of the input periodic signal, to adjust the oscillator to keep the phases matched. Keeping the input and output phase in lockstep also implies keeping the input and output frequencies the same. Consequently, in addition to synchronizing signals, a phase-locked loop can track an input frequency, or it can generate a frequency that is a multiple of the input frequency. These properties are use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency Synthesis
A frequency synthesizer is an electronic circuit that generates a range of frequencies from a single reference frequency. Frequency synthesizers are used in many modern devices such as radio receivers, televisions, mobile telephones, radiotelephones, walkie-talkies, CB radios, cable television converter boxes, satellite receivers, and GPS systems. A frequency synthesizer may use the techniques of frequency multiplication, frequency division, direct digital synthesis, frequency mixing, and phase-locked loops to generate its frequencies. The stability and accuracy of the frequency synthesizer's output are related to the stability and accuracy of its reference frequency input. Consequently, synthesizers use stable and accurate reference frequencies, such as those provided by a crystal oscillator. Types Three types of synthesizer can be distinguished. The first and second type are routinely found as stand-alone architecture: direct analog synthesis (also called a mix-filter-divide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phase Detector
A phase detector or phase comparator is a frequency mixer, analog multiplier or logic circuit that generates a signal which represents the difference in phase between two signal inputs. The phase detector is an essential element of the phase-locked loop (PLL). Detecting phase difference is important in other applications, such as motor control, radar and telecommunication systems, servo mechanisms, and demodulators. Types Phase detectors for phase-locked loop circuits may be classified in two types.Paul Horowitz and Winfield Hill, ''The Art of Electronics 2nd Ed. '' Cambridge University Press, Cambridge, 1989 pg. 644 A Type I detector is designed to be driven by analog signals or square-wave digital signals and produces an output pulse at the difference frequency. The Type I detector always produces an output waveform, which must be filtered to control the phase-locked loop voltage-controlled oscillator (VCO). A type II detector is sensitive only to the relative timing of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Variable Frequency Oscillator
A variable frequency oscillator (VFO) in electronics is an oscillator whose frequency can be tuned (i.e., varied) over some range. It is a necessary component in any tunable radio transmitter or receiver that works by the superheterodyne principle, and controls the frequency to which the apparatus is tuned. Purpose In a simple superheterodyne receiver, the incoming radio frequency signal (at frequency f_) from the antenna is ''mixed'' with the VFO output signal tuned to f_, producing an intermediate frequency (IF) signal that can be processed downstream to extract the modulated information. Depending on the receiver design, the IF signal frequency is chosen to be either the sum of the two frequencies at the mixer inputs ( up-conversion), f_+f_ or more commonly, the difference frequency (down-conversion), f_-f_. In addition to the desired ''IF'' signal and its unwanted image (the mixing product of opposite sign above), the mixer output will also contain the two original frequenci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voltage-controlled Oscillator
A microwave (12–18GHz) voltage-controlled oscillator A voltage-controlled oscillator (VCO) is an electronic oscillator whose oscillation frequency is controlled by a voltage input. The applied input voltage determines the instantaneous oscillation frequency. Consequently, a VCO can be used for frequency modulation (FM) or phase modulation (PM) by applying a modulating signal to the control input. A VCO is also an integral part of a phase-locked loop. VCOs are used in synthesizers to generate a waveform whose pitch can be adjusted by a voltage determined by a musical keyboard or other input. A voltage-to-frequency converter (VFC) is a special type of VCO designed to be very linear in frequency control over a wide range of input control voltages. Types VCOs can be generally categorized into two groups based on the type of waveform produced. * ''Linear'' or '' harmonic oscillators'' generate a sinusoidal waveform. Harmonic oscillators in electronics usually consist of a re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Demodulation
Demodulation is extracting the original information-bearing signal from a carrier wave. A demodulator is an electronic circuit (or computer program in a software-defined radio) that is used to recover the information content from the modulated carrier wave. There are many types of modulation so there are many types of demodulators. The signal output from a demodulator may represent sound (an analog audio signal), images (an analog video signal) or binary data (a digital signal). These terms are traditionally used in connection with radio receivers, but many other systems use many kinds of demodulators. For example, in a modem, which is a contraction of the terms modulator/demodulator, a demodulator is used to extract a serial digital data stream from a carrier signal which is used to carry it through a telephone line, coaxial cable, or optical fiber. History Demodulation was first used in radio receivers. In the wireless telegraphy radio systems used during the first 3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of 4000 Series Integrated Circuits
The following is a list of CMOS 4000-series digital logic integrated circuits. In 1968, the original 4000-series was introduced by RCA. Although more recent parts are considerably faster, the 4000 devices operate over a wide power supply range (generally 3V to 15V, some devices higher ) and are well suited to unregulated battery powered applications and interfacing with sensitive analogue electronics, where the slower operation may be an EMC advantage. The earlier datasheets included the internal schematics of the gate architectures and a number of novel designs are able to 'mis-use' this additional information to provide semi-analog functions for timing skew and linear signal amplification. Due to the popularity of these parts, other manufacturers released pin-to-pin compatible logic devices and kept the 4000 sequence number as an aid to identification of compatible parts. However, other manufacturers use different prefixes and suffixes on their part numbers, and not all devic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signetics
Signetics Corporation was an American electronics manufacturer specifically established to make integrated circuits. Founded in 1961, they went on to develop a number of early microprocessors and support chips, as well as the widely used 555 timer chip. The company was bought by Philips in 1975 and incorporated in Philips Semiconductors (now NXP). History Signetics was started in 1961, by a group of engineers (David Allison, David James, Lionel Kattner, and Mark Weissenstern) who had left Fairchild Semiconductor. At the time, Fairchild was concentrating on its discrete component business (mostly transistors), and its management felt that by making integrated circuits (ICs) it would lose its customers. Signetics founders believed that ICs were the future of electronics (much like another contemporary Fairchild spinoff, Amelco) and wished to commercialize them. The name of the new company was coined from Signal Network Electronics. The venture was financed by a group organized t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auerswald COMander Basic - Mainboard - On Semiconductor HC4046A-3027
Auerswald is a German surname. Notable people with the surname include: * Hans Adolf Erdmann von Auerswald (1792–1848), Prussian general and politician * Rudolf von Auerswald (1795–1866), German (Prussian) official * Heinz Auerswald (1908–1970), German lawyer and member of the SS in Nazi Germany * Ingrid Auerswald Ingrid Auerswald ( Brestrich, born 2 September 1957 in Jena, East Germany) is a retired German athlete who competed mainly in the 100 metres. Biography Brestrich-Lange competed for East Germany in the 1980 Summer Olympics held in Mos ... (born 1957), German athlete {{surname, Auerswald German-language surnames de:Auerswald ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integrated Circuits
An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small flat piece (or "chip") of semiconductor material, usually silicon. Large numbers of tiny MOSFETs (metal–oxide–semiconductor field-effect transistors) integrate into a small chip. This results in circuits that are orders of magnitude smaller, faster, and less expensive than those constructed of discrete electronic components. The IC's mass production capability, reliability, and building-block approach to integrated circuit design has ensured the rapid adoption of standardized ICs in place of designs using discrete transistors. ICs are now used in virtually all electronic equipment and have revolutionized the world of electronics. Computers, mobile phones and other home appliances are now inextricable parts of the structure of modern societies, made possible by the small size and low cost of ICs such as modern compute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Eccles (physicist)
William Henry Eccles FRS (23 August 1875 – 29 April 1966) was a British physicist and a pioneer in the development of radio communication. He was born in Barrow-in-Furness, Lancashire, England. Following graduation from the Royal College of Science, London, in 1898, he became an assistant to Guglielmo Marconi, the Italian radio entrepreneur. In 1901 he received his doctorate from the Royal College of Science. Eccles was an advocate of Oliver Heaviside's theory that a conducting layer of the upper atmosphere could reflect radio waves around the curvature of the Earth, thus enabling their transmission over long distances. Originally known as the Kennelly–Heaviside layer, this region of the Earth's atmosphere became known as the ionosphere. In 1912 Eccles suggested that solar radiation was responsible for the observed differences in radio wave propagation during the day and night. He carried out experiments into atmospheric disturbances of radio waves and used wave detecto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Local Oscillator
In electronics, a local oscillator (LO) is an electronic oscillator used with a mixer to change the frequency of a signal. This frequency conversion process, also called heterodyning, produces the sum and difference frequencies from the frequency of the local oscillator and frequency of the input signal. Processing a signal at a fixed frequency gives a radio receiver improved performance. In many receivers, the function of local oscillator and mixer is combined in one stage called a " converter" - this reduces the space, cost, and power consumption by combining both functions into one active device. Applications Local oscillators are used in the superheterodyne receiver, the most common type of radio receiver circuit. They are also used in many other communications circuits such as modems, cable television set top boxes, frequency division multiplexing systems used in telephone trunklines, microwave relay systems, telemetry systems, atomic clocks, radio telescopes, and milita ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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