System of symbols for domestic integrated circuits. IC classification. IC marking Explanation of the name of the microcircuits

The industry produces a wide range of integrated circuits of varying degrees of integration. In addition to dividing ICs depending on manufacturing technology (film, hybrid, monolithic), ICs are divided into digital and analog. Digital ICs operate with voltages that take only two possible values ​​- logical zero and logical one. Analog ICs can operate with voltages that are continuous in time and value. Depending on the degree of integration, digital ICs either perform individual logical operations (for example, NAND or NOR), or form entire units of digital devices (counters, registers, memory chips, processors, etc.). Analog ICs (operational amplifiers, voltage comparators, timers, DC voltage stabilizers) perform a variety of functions: amplifying signals, generating oscillations of various shapes, modulating and demodulating signals, and many other transformations. Microcircuits designed for digital-to-analog (DAC) and analog-to-digital signal conversion (ADC) are classified as analog.

In the functional diagram of a digital electronic thermometer (temperature range from 0 to 400 o C), the analog part of the device includes a direct current amplifier (DCA) and a 12-bit ADC, and the digital part includes a binary code converter into binary decimal (X/Y) and a decoder DC, which converts this code into a control code for four digital seven-segment indicators (Fig. 2.2).

The standards establish a system of symbols for microcircuits. Most ICs are combined into series, which include a number of different ICs, matched in terms of power supply voltage, input and output signal levels, input and output resistances, and design and technological features. They strive to develop the series so that complete electronic devices can be created from the microcircuits included in it, although it is possible to use ICs of different series in one device.

In the accepted designation system, ICs produced by domestic industry are divided according to their design and technological design into three groups:

a) 1, 5, 6, 7 – semiconductor (monolithic);

b) 2, 4, 8 – hybrid;

c) 3 – other (film, ceramic, etc.).

The symbol of the IC series consists of two elements: the first is a number indicating the design and technological group; the second is a two- or three-digit number indicating the serial number of the series. For example, the series designated by the number 1533 belongs to semiconductor ICs with the serial number of the 533 series.

Based on the nature of the functions performed, ICs are divided into subgroups: generators, amplifiers, triggers, modulators, etc. In turn, subgroups are divided into types. For example, the subgroup “Circuits of digital devices” includes the following types of ICs: registers, adders, pulse counters, decoders, etc. The designations of subgroups and types are standardized. For example, the letters IR in the IC symbol will indicate that this IC from the subgroup “Digital Device Circuits” belongs to the “registers” type. In table 2.1 provides an incomplete classification of types of ICs.

The symbol of a microcircuit consists of a three- or four-digit designation of a series of microcircuits, two letters indicating the subgroup and type of microcircuit, and the serial number of the development of the microcircuit.

The letters (optional) K, KM, KN, KR, and KA, which appear at the beginning of the symbol of the microcircuit, characterize the conditions of its acceptance at the manufacturer, and the letter K means microcircuits of wide application.

To characterize the material and type of housing, the following letters can be added before the digital designation of the series:

R – plastic housing of the DIP type (a housing with rectangular leads perpendicular to the plane of the base of the housing and extending beyond the projection of the body of the housing onto the plane of the base);

Table 2.1

Symbols of microcircuits

Subgroup and type of IC according to functional purpose	Designation	Subgroup and type of IC according to functional purpose	Designation
Shapers: rectangular pulses Computing circuits controllers microprocessors specialized Generators: square wave signals harmonic signals Detectors: amplitude Source schemes secondary power supply: rectifiers Surge Protectors pulse Surge Protectors continuous Digital device circuits: encryptors decryptors counters combined half adders adders registers Switches and keys: voltage		Logic elements: AND–NOT/OR–NOT expanders Modulators: amplitude Converters: digital-analogue analog-digital Memory circuits devices: ROM (mask) UV erasable ROM Comparison schemes: by voltage Triggers type JK (universal) type D (delayed) type T (counting) Amplifiers: operating rooms pulse signals low frequency high frequency Multifunctional circuits: analog digital combined

A – plastic planar case (rectangular case with leads located parallel to the base plane and extending beyond the projection of its body onto the base plane);

M – metal-ceramic case of DIP type;

E – metal-polymer housing of DIP type;

C – glass-ceramic body of DIP type;

I – glass-ceramic planar body;

N – ceramic “leadless” housing.

In the symbols of microcircuits produced in the open-frame version, the letter B is added before the series number. Thus, the open-frame analogues of the regular 155 series are designated B155.

P An example of decoding the designation of the KR1533TM2 microcircuit is shown in Fig. 2.3.

If the schematic diagrams of electronic devices using ICs are made, completely displaying their internal structure using conventional graphic symbols (CGI) of the constituent components, then the diagram will turn out to be very cumbersome and not clear. Displaying the internal structure of an IC on a circuit diagram becomes a kind of redundant information, making it difficult to draw up and read diagrams. It is important for the developer of electronic equipment to know from which functional units a particular device can be created, but the internal structure of the unit is often simply not of interest to him. This explains the fact that when drawing up circuit diagrams of digital and analog devices, only generalized symbols of functional units are used.

The UGO of elements (assemblies) of analog and digital equipment is built on the basis of a rectangle. In its most general form, a UGO can contain a main and two additional fields located on either side of the main one (Fig. 2.4). The size of the rectangle in width depends on the presence of additional fields and the number of characters placed in them, in height - on the number of pins, the intervals between them and the number of lines of information in the main and additional fields. The main field indicates the functional purpose of the element, and the additional fields contain labels indicating functions or pin assignments. At the points where the lead lines are connected, special signs (indicators) are depicted that characterize their special properties (inverse, dynamic, etc.). Groups of pins can be separated by increased spacing or placed in a separate area. According to the standard, the width of the main field must be at least 10 mm, the additional field must be at least 5 mm, and the distance between the terminals must be 5 mm.

The pins of the circuit elements are divided into inputs, outputs, bidirectional pins (serve for both input and output of information) and pins that do not carry information (for example, for connecting power, external R.C.-circuits, etc.). Inputs are shown on the left, outputs on the right, the remaining outputs are on either side of the UGO. If necessary, it is allowed to rotate the designation by an angle of 90 clockwise, i.e. Place the inputs at the top and the outputs at the bottom.

The functional purpose of the element is indicated in the upper part of the main field of the UGO. It is made up of capital letters of the Latin alphabet, Arabic numerals and special characters written without spaces. Examples of designations of main functions are given in table. 2.2. Complex functions are formed from simple ones, placing them in the sequence of signal processing.

The purpose of the pins is indicated by labels placed opposite them in additional fields. Like designations of element functions, they can consist of letters of the Latin alphabet, Arabic numerals and special characters. For example, setting the IC to state “1” is designated as S (Set), and resetting the circuit to the zero state is designated as R (Reset).

Table 2.2

Examples of IC functional designations

	Designation
Random Access Memory (RAM) Read-only memory (ROM)
Logical AND
general designation with shift from left to right with reverse shift
Binary counter
Decimal counter
general designation two-stage
Resistor set
Generator
Comparator (comparison)
Amplifier
Digital-to-analog converter
Analog-to-digital converter

IC pins can be marked with pointers that determine their static and dynamic properties. The signs are placed on the UGO contour line or on the communication line near the UGO contour line from the output line side. Direct static conclusions are depicted by lines attached to the main or additional fields of the UGO without any signs, inverse ones - in the form of a circle at the end. A distinctive feature of dynamic output is a pointer in the form of a slash, arrow or triangle. Conclusions that do not carry logical information are marked with a cross, which is applied either at the point of connection to the UGO (Fig. 2.4) or in the immediate vicinity of it.

According to their functional purpose, the following devices are distinguished in digital ICs.

Logic elements are ICs that implement the basic logical functions NOT, AND, OR and their combinations AND-NOT, OR-NOT, AND-OR-NOT. Part of the LE, in addition to logical operations, performs the functions of power amplifiers.

Drivers . Drivers are considered to be ICs with increased load capacity, the main purpose of which is to organize communication with peripheral devices.

Encryptors . The purpose of the encoder is to transform the input unitary code into natural binary.

Decoders perform functions inverse to encryptors, i.e. convert binary code to unitary code. Special decoders include converters of binary code into control codes for sign-synthesizing indicators.

Multiplexers send one of m input signals to one exit.

Demultiplexers solve the inverse problem - direct one input signal to one of m output channels.

Arithmetic devices are adders binary numbers, multipliers binary numbers, ALU– arithmetic-logical devices, circuits parity,converters binary codes, digital comparators(binary number comparison devices).

Triggers – devices used for memorization logical states.

Registers . A register is a trigger line used for recording, storing, shifting and outputting information.

Counters number of pulses – summing, subtracting, reversing. Counters can serve as programmable divisors frequencies.

Relaxation devices - such as multivibrators and monovibrators.

Memorable devices are designed to record, store and display information.

The degree of integration (indicator of complexity) of an IC is assessed by the number of elements placed on one chip or substrate:

small integrated circuit(MIS) –…………………………. up to 100;

average integrated circuit(SIS) –……………………….. 101 –1000;

large integrated circuit(BIS) – ………………….1001 – 10000;

ultra-large scale integrated circuit(VLSI) – ………..over 100000.

All digital devices can be classified into one of two main classes: combinational (without memory) and sequential (with memory). Combinational are devices whose output state at any time is uniquely determined by the values ​​of the input variables at the same time. These are logical elements, code converters (including encoders and decoders), code distributors (multiplexers and demultiplexers), code comparators, arithmetic-logical devices (adders, subtracters, multipliers, ALUs themselves), read-only memories (ROMs), programmable logic devices matrices (PLM).

Output state sequential of a digital device (finite state machine) at a given moment in time is determined not only by the logical variables at its inputs, but also depends on the order (sequence) of their arrival at previous moments in time. In other words, finite state machines must necessarily contain memory elements that reflect the entire history of the receipt of logical signals, and are executed on flip-flops, while combinational digital devices can be entirely built only on logical elements. Digital devices of the sequential type include flip-flops, registers, counters, random access memory (RAM), microprocessor devices (microprocessors and microcontrollers).

Example 2.1. In the given list of ICs, indicate:

a) digital integrated circuits of combinational type;

b) microcircuits made using hybrid technology;

c) digital integrated circuits of sequential type.

Solution. The combinational ICs in the list include the K133LA3 logical element, the K155KP7 multiplexer, the K564 IM3 adder, and the K556RT5 read-only memory device. The K252PA1 digital-to-analog converter microcircuit is made using hybrid technology, the series number of which begins with the number 2. The sequential ICs include the K561TM2 trigger, the K555IR1 register, the K1533IE6 counter, and the K537RU8 random access memory device. In addition to the listed microcircuits, this list contains an operational amplifier K140UD6, a voltage stabilizer K142EN5, a set of resistors 301HP1A, which belong to analog ICs, and the last microcircuit is made using film technology (the series number begins with the number 3).

In general terms, the name of digital microcircuits consists of a set of letters and numbers and is based on one template adopted in European and American companies. We will analyze it using the example of the AT28C256-15PI microcircuit manufactured by Atmel, which is a typical example of microcircuit marking.

AT	2	8	WITH	256	A	-	15	P	I
1	2	3	4	5	6		7	8	9

The name can be divided into nine parts, in which basic data about the chip is encrypted, such as the manufacturer (1), group (2), group or type of memory (3), manufacturing technology (4), specific type in its group (5 ), an optional field shows the features of this component (6), speed (7), housing type (8), operating temperature range (9). Next, we will consider each of these points in detail.

1. Manufacturer

Most often there are two or three letters that indicate the manufacturer of this component, for example:

AD - Analog Devices
AM-AMD
AT-Atmel
DS - Dallas, National
MC-Motorola

P.S. You can find out more about abbreviations in company names.

2. Group

2 - Permanent memory
4 - Dynamic memory
6 - Random access static memory
7 - Logic
8 - Microprocessors and microcontrollers

3. Memory group or type

0 - Microprocessors
1 - Integrated peripherals/memory - if the number 8 is indicated in field 2, or synchronous memory - if the number 6 is indicated in field 2.
2 - Peripheral - if the number 8 is indicated in field 2 or static RAM - if the number 6 is indicated in field 2.
4 - Serial memory
7 - Electrically programmable memory (UV erasable or one-time programmable)
8 - Electrically reprogrammable memory
9 - Flash memory

P.S."74" - this is logic, it will be discussed separately in the article about logic

4. Production technology

- - NMOS
C - CMOS, low power technology
HC - High CMOS, high-speed CMOS
F - Flash, more related to memory technology
LV - Low Voltage, microcircuits powered by 3.3 volts

P.S. There are significantly more types of technologies in logic; they will be discussed separately in the article about logic

5. Specific type

This figure shows a specific team of chips. For memory, the volume is indicated in kilobits, but you can also estimate the bit depth for memory chips, if the number is 080 then it is 8 Mbit with the organization most likely 1 Mbit for eight bits, if the number is 008 then it is also 8 Mbit, but with the organization 512 Kbit for 16 bits .

6. Features of the component

This field is optional and may be missing. This field contains a letter designation that indicates the distinctive features of this particular component model: such as consumption, performance or additional consumer functions.

7. Performance

Performance is indicated by two or three digits. For processors and microcontrollers it is indicated in megahertz, for memory and PLD in nanoseconds. For older models, a performance index may be indicated, which correlates with the real one, based on specific descriptions of the component.

8. Housing type

9. Operating temperature range

This position contains one letter indicating the operating range of this microcircuit.

Or C - Commercial temperature range (0 ... +70 C)
I - Industrial temperature range (-40 ... +85 C)
A - Automotive temperature range (-40 ... +125 C)
M - Military temperature range (-55 ... +125 C)

P.S

But as with any rule, there are exceptions here, for example, Philips and Intel - these companies mark the temperature range at the beginning of the name of the microcircuit. More details on this issue can be found on the corresponding pages of our server on notation systems.

All produced ICs are divided into three groups according to design and technological features: each group in the symbol system is assigned its own number:

1, 5, 7 – semiconductor ICs (7 – unpackaged);

2, 4, 6, 8 – hybrid ICs;

3 – Other ICs. These include film ICs.

Based on the nature of the functions performed in electronic equipment, ICs are divided into subgroups - generators, amplifiers, modulators and others. Subgroups are divided into types: amplifiers - subgroup, types of amplifiers: high frequency, low frequency and so on.

The elemental base of the equipment consists of a series of ICs - a set of ICs that perform various functions, have a single design and technological base and are intended for joint use in equipment.

The first element is a number corresponding to the design and technological group;

The second element is two or three digits indicating the serial number of the development of this series of ICs; The first two elements, consisting of three to four digits, characterize the full series number of the IC;

The third element is two letters, the first of which characterizes the subgroup, and the second - the species in this subgroup;

The fourth element is the serial number of the IC development in this series, which may contain several ICs identical in their functional purpose.

For widely used microcircuits, the letter K is placed at the beginning of the marking. If the letter P or M is placed after the letter K, it means that the entire series has a plastic or ceramic case.

For example, K174UN7 - IC of wide application (K), series 174, semiconductor technology (1), subgroup of amplifiers (U), type - low frequency, development serial number 7.

Conclusions. 1. The creation of ICs was caused by the need to increase reliability, reduce overall dimensions, weight, and cost of complex electronic equipment. 2. The IC performs a specific function and has a high density of elements.3. All elements of the IC are considered as a single whole. scheme. 4. The advantage of hybrid ICs is ease of manufacture, low labor intensity and low cost compared to semiconductor ICs. 5.The use of MOS transistors in LSIs provides a greater degree of integration due to smaller transistor sizes and smaller insulation area.

Copy control questions:

1.What features does the IC have?

2.What are the criteria for IC classification?

3.Name all the design elements of the IC.

4.What is the difference between hybrid and film ICs?

5. Define the basic set of LSI.

6. Define the degree of integration.

7.What elements of the IC designation system make up the series number?

8.What problems exist in increasing the degree of integration?

9.What are the main features of large-scale integrated circuits?

An integrated circuit (IC) is a functional miniature microelectronic unit that contains transistors, diodes, resistors, capacitors and other radioelements, which are made using the molecular electronics method. Radioelements located in a small volume form a microcircuit for a specific purpose. Based on their design and technological implementation, microcircuits are divided into several main groups: hybrid, semiconductor (monolithic) and film. Hybrid microcircuits are made on a dielectric substrate using discrete radio components mounted by soldering or welding on contact pads. In semiconductor ICs, all circuit elements are formed within the semiconductor die. In film ICs, radioelements are made in the form of films deposited on the surface of a dielectric. All these microcircuits are divided into circuits with a small (up to 10 elements), medium (10... 100 elements) and large (over 100 elements) degree of integration. The industry produces a large number of a wide variety of ICs, which, depending on their functional purpose, are divided into analog and digital (logical). Analog microcircuits are used to generate, amplify and convert signals. Digital ICs are used to process a discrete signal expressed in binary or digital code, so they are more often called logic chips. These microcircuits are used in computer technology, automation and other areas of industry.

Integrated circuits are characterized by the following main parameters:

• Supply voltage Un.

• Power consumption of the element from the power source Рп (in a given mode).

• Noise immunity IP0m, the highest noise voltage at the input of the IC, which does not cause a violation of the correct operation of the element.

Microcircuits retain their parameters only if the technical conditions of their operating standards are met. IS operation standards are usually contained in reference books or the passport attached to them.

Based on their design, ICs are divided into those with a case and those without a case. There are 5 main types of cases:

the first type…………..rectangular with terminals perpendicular to the plane of the base;

the second type……………rectangular with terminals perpendicular to the plane of the base, extending beyond the projection of the housing;

third type……………round;

the fourth type………rectangular with leads located parallel to the plane of the base and extending beyond the body in this plane;

fifth type…………….rectangular “leadless case”.

Marking

The IP marking system determines their technological variety, functional purpose and belonging to a specific series. The IP symbol mainly consists of five elements:

1 element……………letter, indicates the scope of application of the microcircuit in household or industrial equipment;

2 element………….. a figure showing the type of design and technological design (1, 5, 6, 7 semiconductor, 2, 4, 8 hybrid, 3 other);

3 element……………serial number of the series development (2 or 3 digits);

4 element……………functional purpose (two letters, table 2.6);

5th element……………serial number of development according to functional characteristics (number).

At the end of the symbol there may be a letter that characterizes the features of the microcircuit. The first element, a letter, may be missing before the designation of the microcircuit. If the first element is the letter K, then this indicates that the microcircuit is intended for equipment of wide application. An example of decoding the designation of the K118UN2A microcircuit is given in Fig. 2.6.

Table 2.6

Old and new letter designations for integrated amplifiers and secondary power supplies_

Functions performed by microcircuits	Letter designations
		after 1974
Amplifiers:
high frequency
intermediate frequency
low frequency
pulse
direct current
repeaters
video signals
sinusoidal signals
operational and differential
Microcircuits for secondary power supplies:
rectifiers
convert bodies and
Surge Protectors
current stabilizers

Rice. 2.6. An example of decoding the K118UN2A microcircuit

Literature: V.M. Pestrikov. Encyclopedia of amateur radio.

Knowing the general appearance of radio components, you can, of course, understand to some extent the structure of the radio-electronic device, but still the radio amateur will have to draw on paper the contours of the parts and the connection between them.

Back in the last century, in order to preserve the design and circuit solutions of radio devices, the pioneers of radio engineering made drawings of them. If you look at these drawings, you can see that they were made at a very high artistic level.

This was usually done by the inventors themselves, if they had the ability, or by invited artists. Drawings of structures and connections of parts were made from life.

In order not to spend a lot of money on drawing radio devices and to make the work of designers easier, they began to make drawings with simplifications. This made it possible to repeat the design much faster in another city or country and preserve the circuit solutions for posterity. The first drawn diagrams appeared at the beginning of the 19th century.

A lot of time and sometimes money could be spent on drawing an approximate view of a part; in those days it was not yet possible to use computers and programs for drawing diagrams.

The details were drawn in detail. For example, in 1905, an inductor coil was depicted in isometry, that is, in three-dimensional space, with all the details, frame, winding, number of turns (Fig. 1). In the end, images of parts and their connections began to be made conditionally, symbolically, but at the same time preserving their features.

Rice. 1. Evolution of the conventional graphic image of an inductor on electrical circuits

In 1915, the drawing of the circuits was simplified; the frame was no longer depicted; instead, lines of different thicknesses were used to emphasize the cylindrical shape of the coil.

After 40 years, the coil was already depicted with lines of the same thickness, but still preserving the original features of its appearance. Only in the early 70s of our century did the coil begin to be depicted as flat, that is, two-dimensional, and radio-electronic circuits began to take on their current form. Drawing complex electronic circuits is very labor-intensive work. To carry it out, an experienced draftsman-designer is required.

In order to simplify the process of drawing diagrams, the American inventor Cecil Effinger designed a typewriter in the late 60s of the 20th century.

In the machine, instead of the usual letters, symbols for resistors, capacitors, diodes, etc. were inserted. The work of making radio circuits on such a machine became accessible to even a simple typist. With the advent of personal computers, the process of making radio circuits has been greatly simplified.

Now, knowing a graphic editor, you can draw an electronic circuit on a computer screen and then print it on a printer. Due to the expansion of international contacts, the symbols of radio circuits have been improved and now they are not very different from each other in different countries. This makes radio circuits understandable to radio technicians around the world.

The third technical committee of the International Electrotechnical Commission (IEC) deals with the graphic symbols and rules for the execution of electrical circuits.

In radio electronics, three types of circuits are used: block diagrams, circuit diagrams and wiring diagrams. In addition, to check electronic equipment, voltage and resistance maps are drawn up.

Block diagrams do not reveal the specifics of the details, nor the number of ranges, nor the number of transistors, nor according to what scheme these or other nodes are assembled; it only gives a general idea of ​​the composition of the equipment and the interconnection of its individual nodes and blocks. The schematic diagram shows the symbols of the elements of the device or blocks and their electrical connections.

Schematic diagram does not give an idea of ​​​​the appearance, or the location of parts on the board, or how to arrange the connecting wires. This can only be found out from the wiring diagram.

It should be noted that on the wiring diagram the parts are depicted in such a way that their appearance resembles their real outline. To check the operating modes of electronic equipment, special voltage and resistance maps are used. These maps indicate voltage and resistance values ​​relative to the chassis or ground wire.

In our country, when drawing radio-electronic circuits, we are guided by the state standard, abbreviated as GOST, which indicates how certain radio components should be conventionally depicted.

To make it easier to remember the symbols of individual elements of electronic equipment, their images contain characteristic features of the parts. On the diagrams, an alphanumeric designation is placed next to the conventional graphic image.

The designation consists of one or two letters of the Latin alphabet and numbers indicating the serial number of this part in the diagram. Serial numbers of graphic images of radio components are placed based on the sequence of arrangement of similar symbols, for example, in the direction from left to right or from top to bottom.

Latin letters indicate the type of part, C - capacitor, R - resistor, VD - diode, L - inductor, VT - transistor, etc. Next to the alphanumeric designation of the part, the value of its main parameter (capacitance of the capacitor, resistor resistance, inductance, etc.) and some additional information are indicated. The most commonly used conventional graphic images of radio components on circuit diagrams are given in Table. 1, and their letter designations (codes) are given in table. 2.

At the end of the positional designation a letter may be placed indicating its functional purpose, table. 3. For example, R1F is a protective resistor, SB1R is a reset button.

To increase the information richness of a printed publication, in the scientific and technical literature on radio electronics, as well as in various diagrams related to this field of knowledge, conventional letter abbreviations for devices and the physical processes occurring in them are used. In table 4 shows the most commonly used abbreviations and their interpretation.

Table 1. Symbols of radio components on circuit diagrams.

Table 2. Letter designations (codes) of radio components on circuit diagrams.

Devices and elements	Letter code
Devices: amplifiers, remote control devices, lasers, masers; general designation	A
Converters of non-electrical quantities into electrical ones (except for generators and power supplies) or vice versa, analogue or multi-digit converters, sensors for indicating or measuring; general designation	IN
Speaker	VA
Magnetostrictive element	BB
Ionizing radiation detector	BD
Selsyn sensor	Sun
Selsyn receiver	BE
Telephone (capsule)	B.F.
Thermal sensor	VC
Photocell	B.L.
Microphone	VM
Pressure meter	VR
Piezo element	IN
Speed ​​sensor, tachogenerator	BR
Pickup	B.S.
Speed ​​sensor	VV
Capacitors	WITH
Integrated circuits, microassemblies: general designation	D
Integrated analog microcircuit	D.A.
Integrated digital microcircuit, logical element	DD
Information storage device (memory)	D.S.
Delay device	D.T.
Various elements: general designation	E
Lighting lamp	EL
A heating element	EC
Arresters, fuses, protection devices: general designation	F
fuse	F.U.
Generators, power supplies, crystal oscillators: general designation	G
Battery of galvanic cells, batteries	G.B.
Indicating and signaling devices; general designation	N
Sound alarm device	ON
Symbolic indicator	HG
Light signaling device	H.L.
Relays, contactors, starters; general designation	TO
Devices and elements	letter code
Electrothermal relay	kk
Time relay	CT
Contactor, magnetic starter	km
Inductors, chokes; general designation	L
Engines, general designation	M
Measuring instruments; general designation	R
Ammeter (milliammeter, microammeter)	RA
Pulse counter	PC
Frequency meter	PF
Ohmmeter	PR
Recording device	PS
Action time meter, clock	RT
Voltmeter	PV
Wattmeter	PW
Resistors are constant and variable; general designation	R
Thermistor	RK
Measuring shunt	R.S.
Varistor	RU
Switches, disconnectors, short circuits in power circuits (in equipment power supply circuits); general designation	Q
Switching devices in control, signaling and measuring circuits; general designation	S
Switch or switch	S.A.
Push-button switch	S.B.
Automatic switch	SF
Transformers, autotransformers; general designation	T
Electromagnetic stabilizer	T.S.
Converters of electrical quantities into electrical ones, communication devices; general designation	And
Modulator	ive
Demodulator	UR
Discriminator	Ul
Frequency converter, inverter, frequency generator, rectifier	UZ
Semiconductor and electrovacuum devices; general designation	V
Diode, zener diode	VD
Transistor	VT
Thyristor	VS
Electrovacuum device	VL
Devices and elements	Letter code
Microwave lines and elements; general designation	W
Coupler	WE
Koro tkoea we ka tel	W.K.
Valve	W.S.
Transformer, phase shifter, heterogeneity	W.T.
Attenuator	W.U.
Antenna	W.A.
Contact connections; general designation	X
Pin (plug)	XP
Socket (socket)	XS
Demountable connection	XT
High frequency connector	XW
Mechanical devices with electromagnetic drive; general designation	Y
Electromagnet	YA
Electromagnetic brake	YB
Electromagnetic clutch	YC
Terminal devices, filters; general designation	Z
Limiter	ZL
Quartz filter	ZQ

Table 3. Letter codes for the functional purpose of a radio-electronic device or element.

	Letter code
Auxiliary	A
Counting	WITH
Differentiating	D
Protective	F
Test	G
Signal	N
Integrating	1
Gpavny	M
Measuring	N
Proportional	R
State (start, stop, limit)	Q
Return, reset	R
Functional purpose of the device, element	letter code
Memorizing, recording	S
Synchronizing, delaying	T
Speed ​​(acceleration, braking)	V
Summing	W
Multiplication	X
Analog	Y
Digital	Z

Table 4. The most common conventional letter abbreviations in radio electronics, used on various circuits in technical and scientific literature.

Literal reduction	Decoding abbreviation
A.M.	amplitude modulation
AFC	automatic frequency adjustment
APCG	automatic local oscillator frequency adjustment
APChF	automatic frequency and phase adjustment
AGC	automatic gain control
ARYA	automatic brightness adjustment
AC	acoustic system
AFU	antenna-feeder device
ADC	analog-to-digital converter
frequency response	amplitude-frequency response
BGIMS	large hybrid integrated circuit
NOS	wireless remote control
BIS	large integrated circuit
BOS	signal processing unit
BP	power unit
BR	scanner
DBK	radio channel block
BS	information block
BTK	personnel blocking transformer
Letter abbreviation	Decoding the abbreviation
BTS	blocking transformer line
BOO	Control block
BC	chroma block
BCI	integrated color block (using microcircuits)
VD	video detector
VIM	time-pulse modulation
VU	video amplifier; input (output) device
HF	high frequency
G	heterodyne
GW	playback head
GHF	high frequency generator
GHF	hyper high frequency
GZ	start generator; recording head
GIR	heterodyne resonance indicator
GIS	hybrid integrated circuit
GKR	frame generator
GKCH	sweep generator
GMW	meter wave generator
GPA	smooth range generator
GO	envelope generator
HS	signal generator
Reduction	Decoding the abbreviation
GSR	line scan generator
gss	standard signal generator
yy	clock generator
GU	universal head
VCO	voltage controlled generator
D	detector
dv	long waves
dd	fractional detector
days	voltage divider
dm	power divider
DMV	decimeter waves
DU	remote control
DShPF	dynamic noise reduction filter
EASC	unified automated communication network
ESKD	unified system of design documentation
zg	audio frequency generator; master oscillator
zs	slowing system; sound signal; pickup
AF	audio frequency
AND	integrator
ICM	pulse code modulation
ICU	quasi-peak level meter
ims	integrated circuit
ini	linear distortion meter
inch	infra-low frequency
and he	reference voltage source
SP	power supply
ichh	frequency response meter
To	switch
KBV	traveling wave coefficient
HF	short waves
kWh	extremely high frequency
KZV	recording-playback channel
CMM	pulse code modulation
Literal reduction	Decoding the abbreviation
kk	frame deflection coils
km	coding matrix
cnc	extremely low frequency
efficiency	efficiency
KS	deflection system line coils
ksv	standing wave ratio
ksvn	voltage standing wave ratio
CT	check Point
KF	focusing coil
TWT	traveling wave lamp
lz	delay line
fishing	back wave lamp
LPD	avalanche diode
lppt	tube-semiconductor TV
m	modulator
M.A.	magnetic antenna
M.B.	meter waves
TIR	metal-insulator-semiconductor structure
MOP	metal-oxide-semiconductor structure
ms	chip
MU	microphone amplifier
neither	nonlinear distortion
LF	low frequency
ABOUT	common base (switching on a transistor according to a circuit with a common base)
VHF	very high frequency
oi	common source (turning on the transistor *according to a circuit with a common source)
OK	common collector (switching on a transistor according to a circuit with a common collector)
onch	very low frequency
oos	negative feedback
OS	deflection system
OU	operational amplifier
OE	common emitter (connecting a transistor according to a circuit with a common emitter)
Reduction	Decoding the abbreviation
Surfactant	surface acoustic waves
pds	two-speech set-top box
Remote control	remote control
pcn	code-voltage converter
pnc	voltage-to-code converter
PNC	converter voltage frequency
village	positive feedback
PPU	interference suppressor
pch	intermediate frequency; frequency converter
ptk	tv channel switch
PTS	full TV signal
Vocational school	industrial television installation
PU	preliminary effort
PUV	playback pre-amplifier
PUZ	recording pre-amplifier
PF	bandpass filter; piezo filter
ph	transfer characteristic
pcts	full color television signal
Radar	line linearity regulator; radar station
RP	memory register
RPCHG	manual adjustment of local oscillator frequency
RRS	line size control
PC	shift register; mixing regulator
RF	notch or stop filter
REA	radio-electronic equipment
SBDU	wireless remote control system
VLSI	ultra-large scale integrated circuit
NE	medium waves
SVP	touch program selection
Microwave	ultra high frequency
sg	signal generator
SDV	ultralong waves
Reduction	Decoding the abbreviation
SDU	dynamic light installation; remote control system
SK	channel selector
SLE	all-wave channel selector
sk-d	UHF channel selector
SK-M	meter wave channel selector
CM	mixer
ench	ultra-low frequency
JV	grid field signal
ss	clock signal
ssi	horizontal clock pulse
SU	selector amplifier
sch	average frequency
TV	tropospheric radio waves; TV
TVS	line output transformer
tvz	audio output channel transformer
tvk	output frame transformer
TIT	television test chart
TKE	temperature coefficient of capacitance
tka	temperature coefficient of inductance
tkmp	temperature coefficient of initial magnetic permeability
tkns	temperature coefficient of stabilization voltage
tks	temperature coefficient of resistance
ts	network transformer
shopping center	television center
tsp	color bar table
THAT	technical specifications
U	amplifier
UV	playback amplifier
UVS	video amplifier
UVH	sample-hold device
UHF	high frequency signal amplifier
Literal reduction	Decoding the abbreviation
UHF	UHF
UZ	recording amplifier
Ultrasound	audio amplifier
VHF	ultrashort waves
ULPT	unified tube-semiconductor TV
ULLTST	unified lamp-semiconductor color TV
ULT	unified tube TV
UMZCH	audio power amplifier
CNT	unified TV
ULF	low frequency signal amplifier
UNU	voltage controlled amplifier.
UPT	DC amplifier; unified semiconductor TV
HRC	intermediate frequency signal amplifier
UPCHZ	intermediate frequency signal amplifier?
UPCH	intermediate frequency image amplifier
URCH	radio frequency signal amplifier
US	interface device; comparison device
USHF	microwave signal amplifier
USS	horizontal sync amplifier
USU	universal touch device
UU	control device (node)
UE	accelerating (control) electrode
UEIT	universal electronic test chart
PLL	phase automatic frequency control
Literal reduction	Decoding the abbreviation
HPF	high pass filter
FD	phase detector; photodiode
FIM	pulse phase modulation
FM	phase modulation
LPF	low pass filter
FPF	intermediate frequency filter
FPCHZ	audio intermediate frequency filter
FPCHI	image intermediate frequency filter
FSI	lumped selectivity filter
FSS	concentrated selection filter
FT	phototransistor
FCHH	phase-frequency response
DAC	digital-to-analog converter
Digital computer	digital computer
CMU	color and music installation
DH	central television
BH	frequency detector
CHIM	pulse frequency modulation
world championship	frequency modulation
shim	pulse width modulation
shs	noise signal
ev	electron volt (e.V)
COMPUTER.	electronic computer
emf	electromotive force
ek	electronic switch
CRT	cathode-ray tube
AMY	electronic musical instrument
emos	electromechanical feedback
EMF	electromechanical filter
EPU	record player
Digital computer	electronic digital computer

Literature: V.M. Pestrikov. Encyclopedia of amateur radio.