Electronics

Electronics (from the Greek Ηλεκτρόνιο "electron") is a field of science and technology that deals with the creation and practical use of various electronic devices and devices, the operation of which is based on changing the concentration and movement of charged particles (electrons) in a vacuum, gas or solid crystalline bodies, and other physical phenomena (NBIC).

It is also an abbreviated name for electronic equipment.

History

The emergence of electronics was preceded by the discovery and study of electricity, electromagnetism, and then the invention of radio. Since radio transmitters were immediately used (primarily on ships and in military affairs), they required an element base, the creation and study of which was taken up by electronics. The element base of the first generation was based on vacuum tubes. Accordingly, vacuum electronics has been developed. It was also aided by the invention of television and radar, which were widely used during World War II.

But vacuum tubes had significant drawbacks. First of all, these are large sizes and high power consumption (which was critical for portable devices). Therefore, solid-state electronics began to develop, and diodes and transistors began to be used as an element base.

Further development of electronics is associated with the advent of computers. Transistor-based computers were large and power-consuming, as well as unreliable (due to the large number of parts). To solve these problems, microassemblies began to be used, and then microcircuits. The number of chip elements gradually increased, and microprocessors began to appear. At present, the development of electronics is facilitated by the advent of cellular communications, as well as various wireless devices, navigators, communicators, tablets, etc.

Before the advent of electronic computers, logic operations were performed on electromechanical or mechanical relays. In 1943, the Mark-1 electromechanical computer performed one addition operation in 0.3 seconds In the middle of the 20th century, however, the use of an electric vacuum device invented by Lieben (1912) and Lee de Forest (1906) began to be used, the triode, the current of which could be controlled by means of a grid, which made it possible to control the signal^. In 1939, the first vacuum tube computer (J. Atanasoff) appeared, where calculations were performed using logical operations^. In 1946, the Eniac vacuum computer appeared, containing 17,468 lamps, which had to be checked during installation. This machine could perform 5,000 addition operations ^{per second.}

The introduction of the first transistor in 1947, created by William Shockley, John Bardeen, and Walter Brattain, enabled the transition to solid-state logic, and the subsequent invention of the metal-oxide-semiconductor structure was a major milestone in the development of electronics leading to the creation of the integrated circuit and the subsequent development of microelectronics, a major field of modern electronics[^14][15].

Electronics

A distinction can be made between the following areas of electronics:

• Physics (microcosm, semiconductors, electromagnetic waves, magnetism, electric current, etc.) is a field of science that studies the processes that occur with charged particles.
• Consumer electronics are consumer electronic appliances and devices that use electrical voltage, electric current, electric field, or electromagnetic waves. (e.g. TV, mobile phone, iron, light bulb, electric stove,.. etc.).
• Energy – generation, transportation and consumption of electricity, high-power electrical appliances (e.g. electric motor, power plant), electric heating system, power transmission line.
• Microelectronics are electronic devices that use microcircuits as active elements:
  • Optoelectronics – devices that use electric current and photon fluxes,
  • Audio-video equipment – devices for amplifying and converting sound and video images,
  • Digital microelectronics are devices based on microprocessors or logic chips. For example: electronic calculator, computer, digital TV, mobile phone, printer, robot, control panel of industrial equipment, means of transportation, and other household and industrial devices.

An electronic device can include a wide variety of materials and environments where the electrical signal is processed using different physical processes. But in any device, there must be an electrical circuit.

Many scientific disciplines of technical universities are devoted to the study of various aspects of electronics.

Solid-state electronics

History of solid-state electronics

The term solid-state electronics appeared in the literature in the middle of the 20th century to designate devices based on semiconductor elements: transistors and semiconductor diodes, which replaced bulky low-efficiency electric vacuum devices — radio tubes. The root "hard" is used here because the process of controlling the electric current takes place in the solid of the semiconductor, as opposed to a vacuum, as it did in an electron tube. Later, at the end of the 20th century, this term lost its meaning and gradually fell out of use, since almost all electronics of our civilization began to use exclusively semiconductor solid-state active element base.

Device miniaturization[edit]edit code]

With the birth of solid-state electronics, a revolutionary, rapid process of miniaturization of electronic devices began. Over the past few decades, the active elements have shrunk dramatically: while the size of the tubes was a few centimeters, the size of modern transistors integrated on a semiconductor chip is tens of nanometers. Modern integrated circuits can contain several billion of these transistors.

Element Production Technology

Active and passive elements in solid-state electronics are created on a homogeneous ultrapure semiconductor crystal, most often silicon, by injection or sputtering of new layers of atoms of other chemical elements, molecules of more complex substances, including organic substances, at certain coordinates of the crystal body. Injection changes the properties of a semiconductor at the injection site (doping), changing its conductivity to the opposite, thus creating a diode or transistor or passive element: a resistor, a conductor, a capacitor or an inductor, an insulator, a heat dissipation element, and other structures. In recent years, the technology of producing light sources on a chip has become widespread. A huge number of discoveries and developed technologies for the use of solid-state technologies are still lying in the safes of patent holders, waiting in the wings.

The technology for producing semiconductor crystals, the purity of which makes it possible to create elements several nanometers in size, began to be called nanotechnology, and the branch of electronics began to be called microelectronics.

In the 1970s, in the process of miniaturization of solid-state electronics, there was a split into analog and digital microelectronics. In the conditions of competition in the market of manufacturers of the element base, manufacturers of digital electronics won. And in the 21st century, the production and evolution of analog electronics has practically stopped. Since in reality all consumers of microelectronics usually require continuous analog signals or actions from them rather than digital, digital devices are equipped with DACs at their inputs and outputs.

The miniaturization of electronic circuits was accompanied by an increase in the speed of devices. For example, the first digital TTL devices required microseconds to switch from one state to another and consumed a large current, which required special measures to dissipate heat.

At the beginning of the 21st century, the evolution of solid-state electronics towards miniaturization of elements gradually came to a halt and is now practically stopped. This shutdown was predetermined by the achievement of the smallest possible size of transistors, conductors and other elements on the semiconductor chip that are still able to remove the heat generated by the current flow and not be destroyed. These dimensions have reached a few nanometers, and therefore the technology of making microchips is called nanotechnology.

The next stage in the evolution of electronics may be optoelectronics, in which the supporting element will be a photon, much more mobile, less inertial than an electron/"hole" in the semiconductor of solid-state electronics.

Basic solid-state devices

The main solid-state active devices used in electronic devices are:

• A diode is a conductor with one-way conductivity from the anode to the cathode. Varieties: tunnel diode, avalanche-span diode, Gann diode, Schottky diode, etc.;
• Bipolar transistors are transistors with two physical p-n junctions, the collector-emitter current of which is controlled by the base-emitter current;
• A field-effect transistor is a transistor whose Source-Drain current is controlled by the Voltage at the p-n- or n-p-junction gate-drain or the potential on it in transistors without a physical junction, with a gate galvanically isolated from the Stock-Source channel;
• Conductivity controlled diodes, dinistors and thyristors used as switches, LEDs and photodiodes used as converters of electromagnetic radiation into electrical signals or electrical energy or vice versa;
• An integrated circuit is a combination of active and passive solid-state elements on one or more chips in a single package, used as a module, electronic circuit in analog and digital microelectronics.

Use cases

Examples of the use of solid-state devices in electronics:

• Voltage multiplier on rectifier diode;
• Frequency multiplier on a nonlinear diode;
• Emitter repeater (voltage) on a bipolar transistor;
• Collector amplifier (power) on a bipolar transistor;
• Inductor on integrated circuits, capacitors and resistors;
• Input impedance converter on a field-effect or bipolar transistor, on an integrated circuit of an operational amplifier in analog and digital microelectronics;
• Electrical signal generator on a field-field diode, Schottky diode, transistor or integrated circuit in alternating current signal generators;
• Rectifier on rectifier diode in AC circuits in a variety of devices;
• Source of stable voltage on zener diode in voltage stabilizers;
• A source of stable voltage on a rectifier diode in base-emitter voltage offset circuits of a bipolar transistor;
• Light-emitting element in LED lighting fixture ;
• Light-emitting element in LED optoelectronics;
• Light-Receiving Element in Photodiode Optoelectronics;
• Light-receiving element in solar panels of solar power plants;
• Power amplifier on bipolar or field-effect transistor, on an integrated circuit, Power amplifier in the output stages of signal, AC and DC power amplifiers;
• Logic element on a transistor, diodes or on an integrated circuit of digital electronics;
• A memory cell on one or more transistors in memory chips;
• A high-frequency amplifier on a transistor;
• Digital Signal Processor on Digital Microprocessor Integrated Circuit;
• Analog Signal Processor on Trasitors, Analog Microprocessor Integrated Circuit or Op-Amps ;
• Computer peripherals based on integrated circuits or transistors;
• Input stage of an op-amp or differential amplifier on a transistor;
• Electronic key in signal switching circuits on a field-effect transistor with an isolated gate;
• Electronic key in circuits with memory on a Schottky diode.

Main Differences Between Analog and Digital Electronics

Because analog and digital circuits encode information differently, they also have different signal processing processes. At the same time, all operations that can be performed on the analog signal (in particular, amplification, filtering, range limitation, etc.) can also be carried out by methods of digital electronics and software modeling in microprocessors.

The main difference between analog and digital electronics can be found in the most characteristic methods of encoding information for a particular electronics.

Analog electronics uses the simplest proportional one-dimensional coding, i.e. the reflection of the physical parameters of an information source into similar physical parameters of an electric field or voltage (amplitudes into amplitudes, frequencies into frequencies, phases into phases, etc.).

Digital electronics use n-dimensional coding of the physical parameters of the data source. Minimally, digital electronics uses two-dimensional coding: voltage (current) and moments in time. This redundancy is used solely to ensure data transmission with any programmable level of noise and distortion added to the original signal. In more complex digital circuits, software microprocessor processing methods are used. Digital data transmission methods make it possible to create physical data transmission channels without loss (without increasing noise and other distortions)

In the physical sense, the behavior of any digital electronic circuit and the entire device does not differ in any way from the behavior of an analog electronic device or circuit and can be described by the theory and rules describing the functioning of analog electronic devices.

Noise

According to the way information is encoded in analog circuits, they are significantly more vulnerable to noise than digital circuits. A small change in the signal can make significant modifications to the transmitted information and ultimately lead to its loss; In turn, digital signals take only one of two possible values, and in order to cause an error, the interference must be about half of their total value. This property of digital circuits can be used to increase the immunity of signals to interference. In addition, noise countermeasures are provided by signal recovery facilities at each logic gate that reduce or eliminate interference; Such a mechanism is made possible by the quantization of digital signals. As long as the signal stays within a certain range of values, it is associated with the same information.

Noise is one of the key factors that affect signal accuracy; This is mainly the noise present in the original signal and the interference introduced during its transmission (see Signal-to-noise ratio). Fundamental physical constraints, such as so-called "shot" noise in components, set limits on the resolution of analog signals. In digital electronics, additional accuracy is provided by the use of auxiliary digits that characterize the signal; their number depends on the performance of the analog-to-digital converter (ADC).

Development complexity

Analog circuits are more difficult to develop than comparable digital circuits; This is one of the reasons why digital systems have become more widespread than analog ones. Analog circuitry is designed manually, and the process of creating it provides fewer opportunities for automation. In order to interact with the environment in one form or another, a digital electronic device needs an analog interface^. For example, a digital radio has an analog preamplifier, which is the first link in the receiving circuit.

Typology of schemes

Electronic circuits and their components can be divided into two key types depending on the general principles of their functioning: analog (continuous) and digital (discrete). One and the same device can consist of schemes of the same type, or of a mixture of both types in one or another proportion.

Analog circuits

Basically, analog electronic devices and devices (radio receivers, for example) are structurally a combination of several varieties of basic circuits. Analog circuits use a continuous range of voltage, as opposed to the discrete levels used in digital circuits. At the moment, a significant number of different analog circuits have been developed, especially because a "circuit" can mean many things: from a single component to an entire system consisting of thousands of elements. Analog circuits are also sometimes referred to as linear circuits (although some of them, such as transducers or modulators, use many nonlinear effects). Typical examples of analog circuits include vacuum tubes and transistor amplifiers, op-amps, and oscillators.

At present, it is difficult to find such an electronic circuit that would be completely analog. Nowadays, analog circuits use digital or even microprocessor technologies to increase their performance. Such a circuit is usually not called analog or digital, but mixed. In some cases, it is difficult to draw a clear distinction between continuous and discrete circuits because both include both linear and nonlinear elements. An example is a comparator: while receiving a continuous voltage range at the input, it outputs only one of two possible signal levels, similar to a digital circuit. Similarly, an overloaded transistor amplifier can take on the properties of a controlled switch, which also has two levels of output.

Digital schematics

Digital circuits are circuits based on two or more discrete voltage levels^. They represent the most typical physical implementation of Boolean algebra and form the elemental basis of all digital computers. The terms "digital circuit", "digital system" and "logic circuit" are often considered synonymous. Digital circuits are typically characterized by a binary system with two voltage levels that correspond to logic zero and logical one, respectively. Often, the former is associated with low voltage, and the latter with high voltage, although there are also reverse variants. Ternary logic schemes (i.e., with three possible states) were also studied, and attempts were made to build computers based on them. In addition to computers, digital circuits form the basis of electronic clocks and programmable logic controllers (used to control industrial processes); Digital signal processors are another example.

The basic structural elements of this type include:

• Logic gates
• Adders
• Triggers (including Schmitt triggers))
• Counters
• Registers
• Multiplexers

Highly Integrated Devices:

• Microprocessors
• Microcontrollers
• Application-Specific Integrated Circuits (ASICs))
• Digital Signal Processors (DSPs))
• User-programmable gate arrays (FPGAs))

etc.

Reliability of electronic devices

The reliability of electronic devices is made up of the reliability of the device itself and the reliability of the power supply. The reliability of the electronic device itself consists of the reliability of the elements, the reliability of the connections, the reliability of the circuit, etc. Graphically, the reliability of electronic devices is displayed by the failure curve (the dependence of the number of failures on the operating time). A typical failure curve has three sections with different slopes. In the first stage, the number of failures decreases, in the second section, the number of failures stabilizes and almost constantly until the third stage, in the third section, the number of failures constantly increases until the device is completely unusable.

Measuring equipment

Throughout the development of radio-electronic devices and components, there was a need for an objective assessment of the serviceability and parameters of both individual radio parts and finished products. This has led to the need to have a fleet of measuring instruments. Their functional features are very diverse. At the same time, measuring instruments themselves are also a separate field of electronics. The accuracy of measuring equipment is the most important factor that directly affects the quality of the radio equipment developed and debugged with their help. No less important is the observance of the measurement methodology (see Metrology). The most accurate instruments are used for special applications, and are not available to most developers. Entry-level devices (multimeter, laboratory power supply) were often made by enthusiasts themselves.