Electronic components are the general name of components and devices. Electronic components: refers to electronic components whose molecular composition does not change during the production and processing in the factory.

Finished product. Such as resistors, capacitors and inductors. Because it does not produce electrons and has no control and transformation effect on voltage and current, it is also called passive device. Electronic device: refers to the finished product whose molecular structure changes in the process of factory production and processing. Such as transistors, electron tubes and integrated circuits. Also known as active devices, because it can generate electrons, control and transform voltage and current (amplification, switching, rectification, detection, oscillation and modulation, etc. According to the classification standard, electronic devices can be divided into 12 categories, which can be summarized as vacuum electronic devices and semiconductor devices. The development history of electronic components is actually a condensed history of electronic development. Electronic technology is a new technology developed at the end of 19 and the beginning of the 20th century. It developed most rapidly and was widely used in the 20th century, and became an important symbol of the development of modern science and technology.

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abstract

1. components: the products processed by the factory are products with unchanged molecular composition, which can be called components without electronic components.

Equipment that needs energy. It includes: resistance, capacitance and inductance. (also called PassiveComponents) (1) Circuit devices: diodes, resistors, etc. (2) Connecting equipment: connectors, sockets, connecting cables and printed circuit boards (PCB). Devices: Devices whose molecular structure changes in the process of factory production and processing are called devices, which are divided into: 1 and active devices. Its main features are as follows: 2. Discrete devices are divided into (1) bipolar transistors (2) field effect transistors (3) thyristors (4) semiconductor resistors and capacitors.

electric resistance

Resistors are represented by "r" plus numbers in the circuit. For example, R 1 represents the resistance with the number 1. The main functions of resistors in the circuit are: shunt, current limiting, voltage division, bias and so on.

electric capacity

Capacitance is usually represented by "c" plus a number in the circuit (for example, C 13 represents a capacitor with the number 13). Capacitor is an element composed of two metal films, which are adjacent to each other and separated by insulating materials. The characteristic of capacitor is to separate DC from AC. Electronic components.

Capacitance refers to the amount of electric energy that can be stored. Capacitance is called capacitive reactance, which is related to the frequency and capacitance of AC signal.

Transistor diode

Crystal diodes are usually represented by "d" plus numbers in circuits. For example, D5 is represented by the number 5. Function: the main feature of diode is unidirectional conduction, that is, under the action of DC voltage, the on-resistance is very small; However, under the action of reverse voltage, the on-resistance is extremely large or infinite. Because of the above characteristics, diodes are often used in circuits such as rectification, isolation, voltage stabilization, polarity protection, coding control, frequency modulation and static noise. Crystal diodes used in telephones can be divided into rectifier diodes (such as 1N4004) and isolation diodes (such as 1N4 108).

Sensor

Inductance is not widely used in electronic manufacturing, but it is equally important in circuits. We think that inductance, like capacitance, is also an energy storage element, which can convert electric energy into magnetic field energy and store it in the magnetic field. Electronic component of inductor

It means that its basic unit is Henry (H), and it is often used as the unit of millihenry (mH). It often forms LC filters, LC oscillators, etc. together with capacitors. In addition, people also use the characteristics of inductance to make chokes, transformers, relays and so on.

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Integrated circuit is a kind of device with certain functions, which integrates transistors, resistors, capacitors and other elements on a silicon substrate by special technology. The English abbreviation is IC, which is also commonly known as chip. Analog integrated circuit mainly refers to an integrated circuit composed of capacitors, resistors, transistors and other elements for processing analog signals. There are many analog integrated circuits, such as integrated operational amplifiers, comparators, logarithmic and exponential amplifiers, analog multipliers (dividers), phase-locked loops, power management chips and so on. The main circuits of analog integrated circuits are: amplifier, filter, feedback circuit, reference circuit, switched capacitor circuit, etc. Analog integrated circuit design is mainly obtained by experienced designers through manual circuit debugging and simulation, and the corresponding digital integrated circuit design is mostly automatically synthesized by using hardware description language under the control of EDA software. Digital integrated circuit is a digital logic circuit or system that integrates components and wires on the same semiconductor chip. According to the number of gates or components and devices contained in digital integrated circuits, digital integrated circuits can be divided into small-scale integrated (SSI) circuits and medium-scale integrated electronic components.

MSI circuit, LSI circuit, VLSI circuit and ULSI circuit. Small-scale integrated circuits contain no more than 10 gates or no more than 100 elements; The medium-scale integrated circuit contains 10- 100 gates, or the number of components is100-1000; LSI contains more than 100 gates, or the number of components is between 10 and 10; VLSI contains more than 10000 gates, or the number of components is between 10 and 10; The number of components in VLSI is between 10 and 10. It includes: basic logic gate, trigger, register, decoder, driver, counter, shaping circuit, programmable logic device, microprocessor, single chip microcomputer, DSP and so on.

Edit the development history of this paragraph.

The development history of electronic components is actually a condensed history of electronic development. Electronic technology is a new technology developed at the end of 19 and the beginning of the 20th century. It developed most rapidly and was widely used in the 20th century, and became an important symbol of the development of modern science and technology. electronic component

The first generation of electronic products centered on electron tubes. At the end of 1940s, the first semiconductor transistor was born in the world. It has been adopted by many countries because of its small size, portability, power saving and long service life, and has replaced electron tubes in a large range. At the end of 1950s, the first integrated circuit appeared in the world, which integrated many electronic components such as transistors on a silicon chip, making electronic products more miniaturized. Integrated circuits have developed rapidly from small integrated circuits to large-scale integrated circuits and ultra-large-scale integrated circuits, thus making electronic products develop in the direction of high efficiency, low power consumption, high precision, high stability and intelligence. Because the four stages of the development of electronic computers can fully explain the characteristics of the four stages of the development of electronic technology, the following four eras of the development of electronic computers will explain the characteristics of the four stages of the development of electronic technology.

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Electrode material | Optical material | Temperature measuring material | Semiconductor material | Shielding material | Vacuum electronic material | Copper clad laminate material | Piezoelectric crystal material | Electro-optic functional material | Strong current and weak current contact material | Laser working medium | Electronic component film material | Electronic glass | Diamond-like carbon film expansion alloy and thermal bimetal | Electric heating material and other electronic special materials for electric heating elements.

Edit the identification of a single component in this paragraph.

Identification of common products of electronic components. Resistance and resistance are represented by "r" plus numbers in the circuit, for example, R 1 is represented by the number 1. The main functions of resistors in the circuit are shunt, current limiting, voltage division, bias and so on. 1. Parameter identification: the unit of resistance is ohm (ω), and the amplification unit is kiloohm (kω), megaohm (mω), etc. The conversion method is: 1 megohm = 1000 kiloohm = 1000000 ohm. There are three methods to mark the parameters of resistors, namely, direct marking, color marking and digital marking. A, the number scale method is mainly used for small-volume circuits such as patches, for example, 472 means 47×100Ω (that is, 4.7k); 104 means 100K b, and the most commonly used method is color ring labeling. Examples are as follows: four-color ring resistor Five-color ring resistor (precision resistor) 2. The relationship between color code position and resistance magnification is shown in the following table: allowable deviation of color effective digital magnification (%) silver /x 0.0 1 10 gold /x0. 1 5 black 0+0/ brown1/kloc-0. The characteristics of capacitors are mainly blocking DC and circulating AC. The size of the capacitor means the amount of electric energy that can be stored. The blocking effect of capacitance on AC signal is called capacitive reactance, which is related to the frequency and capacitance of AC signal. Capacitance XC= 1/2πfc(f stands for the frequency of AC signal, and c stands for capacitance) The commonly used capacitor types in telephones are electrolytic capacitor, ceramic capacitor, patch capacitor, monolithic capacitor, tantalum capacitor and polyester capacitor. 2. Identification method: The identification method of capacitance is basically the same as that of resistance, which is divided into three methods: direct standard method, color standard method and number standard method. The basic unit of capacitance is farad (F), and other units are millifarad (mF), microfarad (uF), nanofarad (nF) and picofarad (pF). Where: 1 method = 103 millifarad = 106 microfarad = 109 nanofarad =10/2 picofarad, and the capacitance value of the capacitor with large capacity is directly indicated on the capacitor. For example, 10uF/ 16V, the capacitance value of the capacitor is expressed by letters or numbers. Letter representation:1m =1000uf1p 2 =1.2pf1n =1000pf digital representation. For example, 102 means10×102pf =1000pf224 means 22× 104PF=0.22uF3, and the allowable error of the capacitance error table symbol FGJKLM is1%2. 3. Crystal Diodes Crystal diodes are usually represented by "d" plus numbers in circuits. For example, D5 is represented by the number 5. 1, function: the main feature of diode is unidirectional conduction, that is, under the action of DC voltage, the on-resistance is very small; However, under the action of reverse voltage, the on-resistance is extremely large or infinite. Because of the above characteristics, diodes are often used in circuits such as rectification, isolation, voltage stabilization, polarity protection, coding control, frequency modulation and static noise in cordless phones. Crystal diodes used in telephones can be divided into rectifier diodes (such as 1N4004), isolation diodes (such as 1N4 148), Schottky diodes (such as BAT85), light-emitting diodes and zener diodes. 2. Identification method: diode identification is very simple. The N pole (negative pole) of most small power diodes is marked with a colored circle. Some diodes also use diode-specific symbols to indicate the P pole (positive pole) or the N pole (negative pole), while others use symbols such as "P" and "N" to determine diode polarity. The anode and cathode of LED can be identified by the length of the pin, with the long pin being positive and the short pin being negative. 3. Precautions for testing: When testing the diode with a digital multimeter, the red stylus is connected to the anode of the diode, and the black stylus is connected to the cathode of the diode. At this time, the measured resistance is the forward on resistance of the diode, which is just the opposite of the contact pin connection of pointer multimeter. 4. The commonly used 1N4000 series diodes are compared as follows: model1kloc-0/N40021N40031N40041N40051N40005. 50 1 002004006008001000 Current (a) is all1. Zener diodes are usually represented by "ZD" plus numbers in circuits. For example, ZD5 represents Zener diodes with the number 5. 1, Zener diode voltage stabilization principle: The characteristic of Zener diode is that the voltage at both ends remains basically unchanged after breakdown. In this way, when the voltage regulator is connected to the circuit, if the voltage at each point in the circuit changes due to the fluctuation of power supply voltage or other reasons, the voltage at both ends of the load basically remains unchanged. 2. Fault characteristics: The main faults of Zener diode are open circuit, short circuit and unstable regulated value. Among these three faults, the former shows that the power supply voltage rises; The latter two faults are characterized by the power supply voltage becoming low to zero volts or unstable output. Commonly used zener diode models and adjustment values are as follows: model1n47281n47291n47301n47321n47331n4734/kloc-0. 1N476 1V。 In a circuit, inductance is usually represented by "L" plus a number. For example, L6 represents an inductance with a number of 6. The induction coil is made by winding the insulated wire on the insulated skeleton for a certain number of turns. DC can pass through the coil, DC resistance is the resistance of the wire itself, and the voltage drop is very small; When AC signal passes through the coil, self-induced electromotive force will be generated at both ends of the coil, and the direction of self-induced electromotive force is opposite to the direction of applied voltage, which hinders the passage of AC, so the characteristic of inductance is to resist AC through DC. The higher the frequency, the greater the coil impedance. Inductance and capacitance can form an oscillation circuit in the circuit. Inductance generally has direct calibration method and color calibration method, and color calibration method is similar to resistance. For example, brown, black, gold and gold represent the inductance of 1uH (error 5%). The basic unit of inductance is Heng (h), and the conversion unit is:1h =103mh =106uh. The intransitive verb varactor diode is a special diode designed according to the principle that the junction capacitance of "PN junction" in ordinary diodes will change with the change of applied reverse voltage. Varistor is mainly used in the high-frequency modulation circuit of mobile phone or landline in cordless telephone to realize the modulation and transmission of low-frequency signals to high-frequency signals. In the working state, the modulation voltage of varactor diode is generally applied to the negative electrode, which makes the internal junction capacitance of varactor diode change with the modulation voltage. The failure of varactor diode is mainly manifested as leakage or poor performance: (1) When leakage occurs, the high-frequency modulation circuit does not work or the modulation performance is poor. (2) When the performance of the varactor deteriorates, the high-frequency modulation circuit works unsteadily, resulting in distortion after the modulated high-frequency signal is sent to the other party and received by the other party. When one of the above situations occurs, the varactor diode of the same model should be replaced. 7. Transistors are often represented by "q" plus numbers in the circuit, for example, Q 17 represents transistors numbered 17. 1, Features: Transistor (triode for short) is a special device with two PN junctions and amplification capability. There are two types of transistors, NPN and PNP, which can make up for each other in working characteristics. The so-called counter tube in OTL circuit is paired with PNP type and NPN type. PNP transistors commonly used in telephones are: A92, 90 15, etc. NPN transistors include A42,9014,9018,9013,9012, etc. 2. Transistors are mainly used for amplifying circuits, and there are three connection modes for common circuits. For comparison, the characteristics of three transistor connection circuits are listed below. Name * * * Emitter circuit * * Collector circuit (emitter output) * * * The input impedance of the base circuit is large (several hundred ohms to several thousand ohms) and small (several tens ohms to several tens ohms), while the output impedance is small (several thousand ohms to several tens ohms) and large (several tens ohms to several tens ohms). Voltage amplification (less than 1 and close to 1), large current amplification (dozens), large (dozens) and small (less than 1 and close to 1), high power amplification (about 30 ~ 40 dB) and small (about 10 dB). In particular, field effect transistor can be used as the input stage of the whole electronic equipment, and it can obtain the performance that ordinary transistors can not achieve. 2.FET is divided into junction type and insulated gate type, and its control principle is the same. Symbols of two models: 3. Comparison between FET and Transistor (1) FET is a voltage control element and transistor is a current control element. When the signal source only allows a small current, the field effect transistor should be selected; When the signal voltage is low and allows more current to be drawn from the signal source, the transistor should be selected. (2) FET is called unipolar device because it uses majority carriers to conduct electricity, while transistors use both majority carriers and minority carriers to conduct electricity. It is called a bipolar device. (3) The source and drain of some field effect transistors can be used interchangeably, and the gate voltage can be positive or negative, so the flexibility is better than that of transistors. (4) FET can work under the condition of low current and low voltage, and its manufacturing process can easily integrate many FETs on a silicon chip, so FET has been widely used in large-scale integrated circuits. 1) electronic components: refers to the finished products whose molecular composition does not change during the factory production and processing. Such as resistors, capacitors and inductors. Because it does not produce electrons and has no control and transformation effect on voltage and current, it is also called passive device. According to the classification standard, electronic components can be classified into 1 1. 2) Electronic device: refers to the finished product whose molecular structure has changed in the process of factory production and processing. Such as transistors, electron tubes and integrated circuits. Also known as active devices, because it can generate electrons, control and transform voltage and current (amplification, switching, rectification, detection, oscillation and modulation, etc. According to the classification standard, electronic devices can be divided into 12 categories, which can be summarized as vacuum electronic devices and semiconductor devices. The regulating voltage is 3.3v3.6v4.7v5.1v5.6v6.2v15v 27v30v 75v.

Edit this paragraph of photoelectric devices.

Development Trend of Optoelectronic Devices in Optical Networks The basic feature of the next generation optical transport network is super capacity. From the current development of various multiplexing technologies, Dense Wavelength Division Multiplexing (DWDM) is considered as the most effective method to expand network capacity and improve its flexibility. Using DWDM can quickly expand capacity by tens to hundreds of times. Due to the influence of market-driven and technological breakthroughs in recent years, wavelength division multiplexing systems have developed very rapidly. Therefore, all kinds of newly developed optical devices are more or less related to wavelength division multiplexing. The development idea of DWDM has always been to pursue higher spectral efficiency, on the one hand, to improve the rate of each channel, on the other hand, to improve the channel density. At present, the speed of most commercial systems is 2.5Gbit/s or10 gbit/s. The 40Gbit/s system with higher speed is being put into practical use, and it is expected to start commercial application in 2004. Some telecom companies, such as Alcatel, have carried out the transmission experiment of160gbit/s. In terms of channel density, the wavelength gap between channels has been as small as 25GHz, and efforts are still being made to 12.5GHz, so that the total number of channels in commercial systems is now 160~240, and the highest in laboratories is/kloc-0. In order to obtain greater capacity, it is sometimes necessary to compromise between the above two, and at the same time, measures should be taken to suppress dispersion and nonlinear effects in optical fibers. All these requirements are related to the high speed, flexibility and reliability of devices, and finally, the problem of low cost must be considered, which makes devices with new principles, new structures and new functions emerge constantly. In recent years, with the bursting of the "network economy" bubble, the capital expenditure of the optical communication industry has been greatly reduced, and the optoelectronic device industry, as the bottom of the optical communication industry chain, is facing great challenges. It is estimated that in 2002, the capital expenditure of optoelectronic devices for communication in the United States will continue to decrease by 24% on the basis of a sharp decrease of 29% in 200 1 year. On the other hand, the previous blindly optimistic estimation of the market has caused a large backlog of optoelectronic devices, which is estimated to last until 2003. In this market environment, the research and development trend of optoelectronic devices is mainly manifested in the following aspects: (1) From the perspective of the functions realized by optoelectronic devices, the development direction of optoelectronic devices is still larger and smarter optical networks, but the research focus has changed. In terms of system transmission capacity, the research direction of optoelectronic devices will focus on reducing the cost per kilometer per bit of transmission system, rather than blindly pursuing the breakthrough of single fiber transmission rate. There are three schemes to improve optical fiber transmission capacity: expanding optical band, increasing optical channel density and increasing channel speed. In the research of device level, the broadband amplifier combining Raman optical amplifier and EDFA is considered as the most promising photoelectric device when the system is extended to L-band. Wavelength-locked laser, high-power cladding pumped EDFA and high-density group filter will be the key devices in the optical channel density transmission system with the optical channel spacing reduced to 50GHz, 25GHz or even 12.5GHz, and photoelectric devices such as 40Gbit/s high-speed optical modulator and receiver, dynamic dispersion compensator and polarization mode dispersion compensator will be the key devices in the 40Gbit/s channel rate system. The performance and price of these key photoelectric devices will directly affect the design scheme selection of optical transmission system in the future, but the recent key products are still in the 10Gbit/s series, while the 2.5Gbit/s products will gradually decline. (2) Miniaturization and integration are becoming a new trend for optoelectronic devices to remain competitive. With the increasing proportion of photoelectric devices in optical transmission equipment, the requirements for miniaturization of photoelectric devices are becoming more and more obvious. The equipment occupies a small area and consumes low energy, which can effectively reduce the running cost of the network. The miniaturization of optoelectronic devices also promotes the development of integrated technology. Photoelectric integration technology can integrate photonic components with the electronic chips they drive. Planar waveguide integration technology can integrate optical switches, adjustable attenuators, wavelength division multiplexing/demultiplexers and other passive devices. Compared with the system composed of discrete devices, the system that realizes the subsystem function on one chip not only greatly reduces the volume, but also reduces the packaging cost. In the development of miniaturized optical devices, the development trend of assembling optical devices such as lasers/detectors and microelectronic chips into modules with multiple functions is obviously accelerated. Modularization can eliminate the influence of parasitic parameters, improve performance and save the process and cost of subsequent assembly. It also promotes the cooperation and standardization of related industries. For example, a year ago, many enterprises reached an agreement on the optical, electrical and mechanical performance standards of 10Gbit/s transponders, which greatly promoted the improvement of the cost performance of such devices. Functionally, forward error correction (FEC) and hot plug have been widely adopted by high-end products. In terms of size, compared with the traditional plug-in, the integrated transponder module can reduce the size to the original110, reduce the power consumption by 2/3, and the price is only 1/3. Optical transceiver modules, which are mainly used in metropolitan area networks and access networks, are also developing from duplex SC to smaller SFF modules. Compared with the duplex SC package, it occupies a smaller volume on the circuit board, which is 1/2. In terms of optical amplifier, the new EDFA module is only 7cm'9cm' 1.2cm (length' width' height), but it can provide a gain of 24dB and a power output of 15dBm. Modularization has further promoted the progress of microcapsule lasers and uncooled lasers. At present, not only lasers used for optical signal sources, but also power-pumped lasers have made breakthroughs in uncooled technology. The 980nm uncooled laser below 1.20 MW has been commercialized. Due to the cancellation of the cooler, the power consumption of EDFA module is reduced from 4.5W to below 1W, and the volume is also greatly reduced. It is worth noting that recently, erbium-doped waveguide optical amplifier (EDWA) has also been integrated into planar waveguide to overcome the shortcoming of large insertion loss of planar waveguide devices, thus making it possible to manufacture planar waveguide devices with newer and more complex functions. (3) The automation technology of photoelectric device assembly will be the key to reduce the cost of photoelectric devices. Manual assembly is the main factor limiting the further cost reduction of photoelectric devices. Automatic assembly can reduce labor cost, increase output and save production site, so the research on automatic assembly technology of photoelectric devices will be the key to reduce the cost of photoelectric devices. Because the precision of automatic assembly of photoelectric devices is in the sub-micron order, automatic assembly production has always been considered very difficult, but recently there has been a great breakthrough. Foreign academic journals have reported for many times that based on the technical progress of VCSEL, new optical collimating devices and self-alignment, the breakthrough of automatic assembly of optical devices has been realized, and the designs of photoelectric devices specifically for automatic assembly have emerged one after another. At the OFC exhibition in 2002, there were more than ten manufacturers producing automatic packaging and automatic ultrasonic welding machines. Many processes, such as welding, alignment, pressure welding, etc., used to be considered as manual operations, but now they can be completed by robots. According to the forecast of ElectroniCast, by 2005, the sales of automatic assembly and test equipment will reach 1, 7 1 billion dollars, and 70% ~ 80% of the output value of photoelectric devices will be produced by fully automatic or semi-automatic assembly. It can be said that the emergence of automatic production line is the symbol and necessity of the development of optoelectronic industry.