Marking of ceramic capacitors - tables with explanations of symbols

What is a capacitor?

A device that stores electricity in the form of electrical charges is called a capacitor.

The amount of electricity or electric charge in physics is measured in coulombs (C). Electrical capacitance is calculated in farads (F).

A solitary conductor with an electrical capacity of 1 farad is a metal ball with a radius equal to 13 radii of the Sun. Therefore, a capacitor includes at least 2 conductors, which are separated by a dielectric. In simple device designs, paper is used.

The operation of a capacitor in a DC circuit is carried out when the power is turned on and off. Only during transient moments does the potential on the plates change.

The capacitor in the AC circuit recharges at a frequency equal to the frequency of the power source voltage. As a result of continuous charges and discharges, current flows through the element. A higher frequency means the device recharges faster.

The resistance of the circuit with a capacitor depends on the frequency of the current. At zero frequency of direct current, the resistance value tends to infinity. As the AC frequency increases, the resistance decreases.

Operating principle of capacitors

When a circuit is connected to an electrical source, electrical current begins to flow through the capacitor. At the beginning of the passage of current through the capacitor, its strength is at its maximum and the voltage is at its minimum. As the device accumulates charge, the current drops until it disappears completely, and the voltage increases.

During the process of charge accumulation, electrons accumulate on one plate and positive ions on the other. Charge does not flow between the plates due to the presence of a dielectric. This is how the device accumulates charge. This phenomenon is called the accumulation of electric charges, and the capacitor is called an electric field accumulator.

Explanation of capacitor markings

To decipher the marking, you need the meaning of the first two digits indicating the capacity. If the capacitor has very small dimensions that do not allow the capacity to be marked, it is marked according to the EIA standard, which is used for all modern products.

Designation of numbers

If the designation contains only two numbers and one letter, in this case the digital values ​​​​correspond to the capacity of the device. All other markings are deciphered in their own way, in accordance with one design or another.

Characteristics and properties

Capacitor parameters that are used to create and repair electronic devices include:

1. Capacity - C. Determines the amount of charge that the device holds. The value of the nominal capacity is indicated on the case. To create the required values, the elements are included in the circuit in parallel or in series. Operational values ​​do not coincide with calculated values.
2. Resonant frequency - fр. If the current frequency is greater than the resonant one, then the inductive properties of the element appear. This makes work difficult. To ensure the design power in the circuit, it is reasonable to use a capacitor at frequencies below resonant values.
3. Rated voltage - Un. To prevent breakdown of the element, the operating voltage is set less than the rated voltage. The parameter is indicated on the capacitor body.
4. Polarity. If the connection is incorrect, breakdown and failure will occur.
5. Electrical insulation resistance - Rd. Determines the leakage current of the device. In devices, parts are located close to each other. At high leakage current, parasitic connections in the circuits are possible. This leads to malfunctions. Leakage current worsens the capacitive properties of the element.
6. Temperature coefficient - TKE. The value determines how the capacitance of the device changes with fluctuations in ambient temperature. The parameter is used when developing devices for operation in harsh climatic conditions.
7. Parasitic piezoelectric effect. Some types of capacitors create noise in devices when deformed.

Types of markings

At the moment, manufacturers use several types, which can be located on the body either individually or interchangeably. All values ​​below will be purely theoretical, provided for illustrative purposes.

The simplest type of marking - no codes or table substitutions, the capacity is directly written on the body, which immediately provides the end user with real parameters without unnecessary movements. And this method would be used everywhere, if not for its bulkiness - it will be possible to completely write the container only on fairly large products, otherwise it will be impossible to see the inscription even with a magnifying glass. For example: writing 100 µF±6% means that this capacitor has a capacitance of 100 microfarads with a damping of 6% of the total capacitance, which is equal to a value of 94-106 microfarads. It is also possible to use markings of the form 100 µF +8%/-10%, which means unequal damping equal to 90–108 microfarads. This is the simplest and most understandable method, however, such marking is very cumbersome, so it is used on large and very capacitive capacitors.

Marking of large products

Digital marking of capacitors (as well as numerical and alphabetic markings) is used in cases where the small area of ​​​​the product does not allow a detailed record of the capacitance to be placed. Therefore, certain values ​​are replaced with ordinary numbers and Latin letters, which are deciphered one by one to obtain complete information.

Numerical and alphanumeric markings of small capacitors

Everything is very simple - if only numbers are used (and on such products there are usually three of them), then you need to decipher them as follows:

• the first two digits indicate the first two digits of the capacity;
• the third digit indicates the number of zeros that must be added after the first two digits;
• such capacitors are always measured in picofarads.

Let's take for example the first option from the picture above with the entry 104. We leave the first two digits as 10. To them we add the number of zeros indicated by the third digit, that is, 4. We get a value of 100,000 picofarads. We return to the table at the beginning of the article, reduce the number of zeros and get an acceptable value of 100 microfarads.

If one or two digits are used, they remain that way. For example, the notations 5 and 15 represent 5 and 15 picofarads, respectively. The .55 marking is equal to 0.55 microfarads.

An interesting notation is made using letters either instead of a dot or as another quantity. For example, 8n2 means 8.2 nanofarads, while n82 means 0.82 nanofarads. For a certain class of capacitors, an additional code marking may be added at the end, for example, 100V.

Labeling of ceramic capacitors using a numerical and alphabetic method is the standard for these products. Here, exactly the same encryption algorithms are used, and the inscriptions themselves are physically applied by the manufacturer to the ceramic surface.

Ceramic capacitors with markings

• An outdated, but still used option is color indication. It was used in Soviet production to simplify the reading of markings even on very small products. The downside is that it is quite problematic to remember such a table right away, so it is advisable to have it on hand, at least at first. The colors are applied to the capacitors, where the marking is done in the form of monotonous stripes. Read as follows: the first two colors indicate the capacitance in picofarads;
• the third color shows the number of zeros that need to be added;
• the fourth and fifth colors respectively show the possible tolerance and nominal voltage supplied to the product.

Marking of imported capacitors is carried out in similar ways, only the Latin alphabet can be used instead of Cyrillic. For example, on domestic versions there may be 5mk1, which means 5.1 microfarads. Whereas on imported ones this value will look like 5µ If the entry is completely incomprehensible, then you can contact the official manufacturer for clarification; most likely, the website has tables or a program that decipher its markings. However, this occurs only in exceptional cases and is rarely encountered.

Marking of solid capacitors

According to the international standard, they begin to read from units of measurement. Farads are used to measure capacitance. The marking is applied to the body of the device itself.

Sometimes markers are applied that indicate permissible deviations from the norm of the capacitance of the capacitor itself (indicated as a percentage).

Sometimes, instead of them, a letter is used that denotes one or another value of the tolerance itself. Then we determine the rated voltage. In the event that the device body is large, this parameter is indicated by a number, followed by letters. The maximum permissible value of the parameter is indicated using numbers. If there is no information on the housing about the permissible voltage value, then it can only be used in low-voltage circuits. If the device, according to its parameters, should be used in circuits where there is alternating current, then it, accordingly, should be used exactly this way and not otherwise.

A device that operates with direct current cannot be used in circuits with alternating current.

Next, we determine the polarity of the device: positive and negative. This step is very important. If the poles are determined incorrectly, there is a high risk of a short circuit or even explosion of the device itself. Regardless of the polarity, the capacitor can be connected if no information about the plus and minus terminals is indicated.

The polarity value can be applied in the form of special indentations that have the shape of a ring, or in the form of a single-color stripe. In aluminum capacitors, which in appearance resemble a can of cans, such designations indicate negative polarity. But, for example, in tantalum capacitors, which have small dimensions, the opposite is true - the polarity with these designations will be positive. Color coding should not be taken into account only if plus and minus are indicated on the capacitor itself.

Capacitor markings: explanation

The values ​​of the first two digits on the case, which indicate the capacity of the device. If the capacitor is small, marking is carried out according to the EIA standard.

Numbers: designation

When the designation contains only one letter and two numbers, the numbers correspond to the capacitance parameter of the capacitor. You need to decipher the remaining markings in your own way, based on one or another instruction. The zero multiplier is the third digit. Decoding is carried out depending on what number is at the end. A certain number of zeros must be added to the first two digits if the digit is in the range from zero to six. If the last digit is the number eight, then in this case it is necessary to multiply the first two digits by 0.01. When the value of the capacitance of the capacitor becomes known, it will be necessary to determine the units of measurement in which this value is indicated. Ceramic devices, as well as film options, are small. In them, this parameter is measured in picofarads. Microfarads are used for large capacitors.

Letters: their designation

Next, you need to decipher the letters that are in the marking. If there is a letter in the first two characters, then it can be deciphered using several methods. If there is a letter R, then it plays the role of a comma, which is used in a fraction. If there are letters u, n, p, then it also acts as a comma in the same fraction.

Ceramic capacitors: marking

These types of devices have two contacts and a round shape. Both the main indicators and the tolerance for deviations from the capacity parameter will be indicated on the case. To do this, use a special letter, which is located after the designation of the capacity in numbers.

If there is a letter B, then the deviation in this case will be +0.1 pF, if the letter C is + 0.25 pF, and so on. Only when the capacitance parameter value is less than 10pF are these values ​​used. If the capacity parameter is greater than that indicated above, then the letters are the percentage of permissible deviations.

Mixed markings of numbers and letters

The marking can be indicated in the form of a letter, then a number, and then a letter again. The first character is the lowest permissible temperature. The second symbol, on the contrary, indicates the highest permissible temperature. The third symbol is the device capacity, which can change within the previously specified temperature values.

Other markings

The voltage value can be found using the markings located on the device body. The symbols indicate the permissible maximum parameter value for a particular capacitor. Sometimes the markings are simplified. For example, only the first digit is used. A voltage less than ten volts will be designated, for example, by zero, and the same parameter, which will have a voltage ranging from ten to ninety-nine volts, will be designated by one, and so on. Devices that were released much earlier have different markings. Then you need to consult the reference book to avoid making mistakes. Here you can also learn how to test a capacitor on a board with a multimeter.

Code marking of electrolytic capacitors for surface mounting

The following coding principles are used by such well-known companies as Hitachi and others. There are three main coding methods:

A. Marking with 2 or 3 characters

The code contains two or three characters (letters or numbers) indicating the operating voltage and rated capacity. Moreover, the letters indicate voltage and capacitance, and the number indicates the multiplier. In the case of a two-digit designation, the operating voltage code is not indicated.

Rice. 9

Table 14

We advise you to study the Do-it-yourself cable cutting machine

Rice. 10

B. 4-character marking

The code contains four characters (letters and numbers) indicating the capacity and operating voltage. The first letter indicates the operating voltage, the subsequent digits indicate the nominal capacitance in picofarads (pF), and the last digit indicates the number of zeros. There are 2 options for encoding the capacity: a) the first two digits indicate the nominal value in picofarads, the third - the number of zeros; b) the capacitance is indicated in microfarads, the m sign acts as a decimal point. Below are examples of marking capacitors with a capacity of 4.7 μF and an operating voltage of 10 V.

Rice. eleven

C. Two-line marking

If the size of the case allows, then the code is located in two lines: the capacitance rating is indicated on the top line, and the operating voltage is indicated on the second line. Capacitance can be indicated directly in microfarads (µF) or in picofarads (pf) indicating the number of zeros (see method B). For example, the first line is 15, the second line is 35V - means that the capacitor has a capacity of 15 uF and an operating voltage of 35 V.

Rice. 12

Code marking

According to IEC standards, in practice there are four ways to encode the nominal capacity.

Three digit encoding

The first two digits indicate the capacitance value in picofarads (pF), the last two digits indicate the number of zeros. When the capacitor has a capacitance of less than 10 pF, the last digit may be "9". For capacitances less than 1.0 pF, the first digit is “0”. The letter R is used as a decimal point. For example, code 010 is 1.0 pF, code 0R5 is 0.5 pF.

Table 1

* Sometimes the last zero is not indicated.

Four digit encoding

4-digit coding options are possible. But even in this case, the last digit indicates the number of zeros, and the first three indicate the capacity in picofarads (pF).

table 2

Capacitance marking in microfarads

The letter R may be used instead of the decimal point.

Mixed alphanumeric marking of capacity, tolerance, TKE, operating voltage

Unlike the first three parameters, which are marked in accordance with standards, the operating voltage of different companies has different alphanumeric markings.

Examples:

Picture 1

Application

Capacitors are used in almost all areas of electrical engineering. Let's list just a few of them:

• construction of feedback circuits, filters, oscillatory circuits;
• use as a memory element;
• for reactive power compensation;
• to implement logic in some types of protection;
• as a sensor for measuring liquid level;
• for starting electric motors in single-phase AC networks.

Using this radio-electronic element, it is possible to receive high-power pulses, which is used, for example, in photo flashes and in the ignition systems of carburetor engines.

Designation in diagrams

In general, when repairing and re-soldering modern SMD printed circuit boards, it is most convenient when you still have a diagram at hand, looking at which it is much easier to understand what is installed, to find out the location of a certain part, because an SMD capacitor in appearance may not differ at all from the same transistor. The designations of these parts in the circuits remained the same as they were before the arrival of chips on the market, and therefore the capacity and other necessary characteristics can also be easily found by a radio amateur who has not encountered SMD components.

Marking SMD capacitors.

The dimensions of SMD capacitors are small, so their marking is done very succinctly. The operating voltage is often coded by letter (2nd and 3rd options in the figure below) in accordance with the data provided in the previous section. The nominal capacity can be encoded either using a three-digit digital code (option 2 in the figure) or using a two-digit alphanumeric code (option 1 in the figure). When using the latter, you can still find two (and not one letter) with one number on the case (option 3 in the figure).

The first letter can be either a manufacturer's code (which is not always interesting) or indicate the rated operating voltage (more useful information), the second can be an encoded value in picoFarads (mantissa). The number is an exponent (indicates how many zeros need to be added to the mantissa). For example, EA3 may mean that the rated voltage of the capacitor is 16V(E) and the capacitance is 1.0 * 1000 = 1 nanofarad, BF5, respectively, the voltage is 6.3V(V), the capacitance is 1.6 * 100000 = 0.1 microfarad and. etc.

Capacitor marking table

Why is labeling needed?

The purpose of marking electronic components is to allow them to be accurately identified. Capacitor markings include:

• data on the capacitance of the capacitor - the main characteristic of the element;
• information about the rated voltage at which the device remains operational;
• data on the temperature coefficient of the capacitance, which characterizes the process of changing the capacitance of the capacitor depending on changes in ambient temperature;
• percentage of permissible deviation of the capacity from the nominal value indicated on the device body;
• release date.

For capacitors, when connecting which polarity must be observed, information must be provided that allows the element to be correctly oriented in the electronic circuit.

The marking system for capacitors produced at enterprises that were part of the USSR had fundamental differences from the marking system used at that time by foreign companies.

TKE marking

Capacitors with non-standardized TKE

* Modern color coding. Colored stripes or dots. The second color can be represented by the color of the body.

Capacitors with linear temperature dependence

* The actual spread for imported capacitors in the temperature range -55...+85'С is shown in brackets.

** Modern color coding. Colored stripes or dots. The second color can be represented by the color of the body.

Capacitors with nonlinear temperature dependence

* Designation according to EIA standard, IEC in parentheses.

**Depending on the technologies that the company has, the range may be different.

For example, the PHILIPS company for the Y5P group normalizes -55...+125 °C.

***According to EIA. Some companies, such as Panasonic, use a different encoding.

Features of coding capacitors made in the USSR

In the USSR, IEC standards were followed, so you can use the above data, but there were also minor differences.

The coded designation of nominal capacities consists of two or three numbers and a letter. The code letter is a multiplier that makes up the capacitance value (see table) and determines the position of the decimal fraction.

The permissible deviation of the capacitance value as a percentage of the nominal value is indicated by the same letters as the tolerances for the resistance of resistors, however, with some additions (see table). For capacitors with a capacitance of less than 10 pF, the permissible deviation is set in picofarads :

Capacitors are marked with a code in the following order:

• rated capacity;
• permissible deviation of capacity;
• TKE and (or) rated voltage.

Here are examples of coded marking of capacitors.

The abbreviated alphanumeric marking on the 33pKL capacitor indicates a nominal capacitance of 33 pF with a tolerance of ±10% and temperature instability of the M75 group (75x10-6 °C-1). The inscription m10SF indicates 100 µF (0.1 millifarads) with a tolerance of -20...+50% and a nominal voltage of 20 V.

A nominal capacitance of 150 pF can be designated 150p or n15; 4700pf - 4n7; 0.15 µF - µ15; 2.2μF - 2μ2.

Note. The old tolerance designation is indicated in parentheses.

Fixed capacitors

Fixed capacitors are used in various circuits to separate the alternating and direct current components and smooth out the ripple of rectifier voltages. In combination with other circuit elements, capacitors form resonant circuits widely used in radio equipment. Fixed capacitors are classified according to their rated capacitance, accuracy class, rated operating voltage, purpose, dielectric material and design features.

The nominal values ​​of capacitances of capacitors are established by GOST 2519 - 60. During the manufacture of capacitors, the actual value of the capacitance differs from the nominal value indicated in the marking. The permissible deviation of the capacitance from the nominal value is called tolerance. According to this principle, all capacitors are divided into five classes: 0, 1, II, III, IV, their tolerances are respectively ±2%; ±5%; ±10%; ±20% and from - 20 to + 50%.

Ceramic high voltage capacitor.

Depending on the purpose, there are loop, separating, blocking and filter capacitors. Based on the dielectric material, capacitors are divided into mica, ceramic, paper, metal-paper, paper-oil, film, glass-enamel, glass-ceramic, electrolytic, air, vacuum, gas-filled. Based on their design, capacitors are divided into tubular, disk, barrel, pot, crimped and sealed, flat and cylindrical, etc.

Regardless of the type, the capacitor is characterized by its operating voltage. The operating voltage is the voltage under which the capacitor plates can remain for a long time without breakdown of the dielectric separating them. Operating voltage is expressed in volts. Of great importance for the normal operation of the capacitor is the resistance of its insulation. With low insulation resistance, leaks occur that disrupt the normal operation of the circuit. Losses in a capacitor are characterized by the dielectric loss tangent, which expresses the ratio of the power of active losses to the reactive power of the capacitor.

In low-power capacitors, energy losses are mainly caused by dielectric conductivity and dielectric hysteresis, i.e., losses due to rotation of polar molecules in the direction of the field when voltage is applied to the plates. Losses in the plates and leads are small, so they are usually neglected. One of the most important characteristics of a capacitor is stability—the constant value of the capacitor’s capacitance during operation. The change in capacity can be either temporary or irreversible. The main factor influencing the stability of the capacitance of the capacitor is the effect of ambient temperature and heating of the capacitor due to the power dissipated on it. As the temperature rises, the geometric dimensions of the material increase, which entails a temporary (until the temperature returns to its original value) change in capacity.

Mechanism and structure

The composition of ceramic BaTiO3 is an aggregate made up of microcrystals ranging from 1 to 20 millimeters in diameter. This microcrystal is called a particle, and consists of a crystal structure, which is shown in Fig. 1 and 2. The particle is divided into many domains at a temperature below the Curie point. The crystal axes are aligned in the same direction within the domain, thus similar to spontaneous polarization. When heated to the Curie point and above, the crystal structure of BaTiO3 changes from tetragonal to cubic. Then, spontaneous polarization and domain walls disappear (disappear).

Structure of a ceramic capacitor.

When BaTiO3 is cooled (below the Curie point), its crystal structure rotates from cubic to quadrangular, segments up to about 1% along the C axis and along other axes are shortened. Then spontaneous polarization and domain walls appear. At the same time, the particles are distorted by influence “from outside”. At this stage, many small domain walls are generated, and the direction of spontaneous polarization in each domain can easily be completely changed, even by small (low) electric fields. Since the dielectric constant is proportional to the amount of spontaneous polarization inversion per unit volume, a large capacitance is observed.

When capacitors are stored (used) without load at temperatures below the Curie Point, the size of the randomly oriented domains becomes large and they (domains) gradually shift to a stable energy state (Fig. 3, 90 domains). This also makes it easier to collect residual stress from crystalline distortion.

In addition, the movement of space charges (ions with low mobility, free points of the crystal lattice, etc.) within the domain wall leads to polarization of the space charge. This space charge polarization adversely affects the spontaneous polarization, preventing its reversal.

In other words, the temporary transition from the generation of spontaneous polarization (spontaneous polarization is gradually rearranged to a more stable state) to inversion is complicated by the appearance of space charge polarization. In this state, a higher electric field is needed to reverse the spontaneous polarization in the domains, which in turn can be reversed by low electric field decreases and capacitance reductions. This is believed to be the mechanism of aging.

However, the microtexture of the crystal lattice returns to its original state when heated to a temperature above the Curie Point, at which point aging of the lattice begins all over again. In general, the capacitance of a multilayer ceramic capacitor with a high dielectric constant decreases approximately linearly on a logarithmic time scale - within 24 hours after heat treatment above 125 C. Please refer to the attached typical aging data of our products and the rated capacitance of capacitors. Capacitance, which has decreased as a result of natural aging, tends to be restored when the capacitors are heated to the Curie point and above.

The expected capacitance of a multilayer ceramic capacitor will be at its nominal value when these conditions are set on the equipment. We choose our capacitance amplitude based on the previous assumption. By the way, the temperature compensating values ​​of typical capacitors do not exhibit the phenomenon of aging.

Ceramic capacitors of standard parameters.

Ceramic and glass-ceramic capacitors with a solid inorganic dielectric layer are available in high-voltage and low-voltage versions. They are compact in size and reliable. Widely in demand in computing, household, medical, military equipment, and transport. Based on their rated voltage, they are divided into high- and low-voltage.

The following ceramic capacitors are produced by design type:

• KTK – tubular;
• KDK – disk;
• SMD – surface and others.

To make ceramic capacitors, they do not use baked clay, but materials similar to it in structure - ultraporcelain, tikond, ultrasteatite. The lining is a silver layer. Ceramic and glass-ceramic devices are used in circuits in which frequency characteristics, low leakage losses, compact dimensions, and low cost are important.

Units

The easiest way is to calculate the capacitance of a flat capacitor.
If the linear dimensions of the plates-plates significantly exceed the distance between them, then the formula is valid: C= e*S/d

e is the value of the electrical permittivity of the dielectric located between the plates.

• S – area of ​​one of the plates (in meters).
• d – distance between plates (in meters).
• C is the capacitance value in farads.

What is a farad? For a capacitor with a capacity of one farad, the voltage between the plates rises by one volt when receiving electrical energy in an amount of one coulomb. This amount of energy flows through the conductor within one second, at a current of 1 ampere. The farad received its name in honor of the famous English physicist - M. Faraday.

1 farad is a very large capacitance. In everyday practice, capacitors of much smaller capacity are used and derivatives of farads are used for designation:

• 1 Microfarad – one millionth of a farad.10-6
• 1 nanofarad is one billionth of a farad. 10-9
• 1 picofarad -10-12 farads.

Four-digit marking

This marking is similar to that described above, but in this case the first three digits determine the mantissa, and the last is the exponent in base 10 to obtain the capacitance in picofarads. For example, 1622 = 162*102 pF = 16200 pF = 16.2 nF.

Capacitor markings.

Alphanumeric marking

With this marking, the letter indicates the decimal point and designation (uF, nF, pF), and the numbers indicate the capacitance value:

15p = 15 pF, 22p = 22 pF, 2n2 = 2.2 nF, 4n7 = 4.7 nF, μ33 = 0.33 µF

It is often difficult to distinguish the Russian letter “p” from the English “n”. Sometimes the letter R is used to indicate the decimal point. Usually capacitances are marked in microfarads, but if the letter R is preceded by a zero, then these are picofarads, for example: 0R5 = 0.5 pF, R47 = 0.47 µF, 6R8 = 6.8 µF .

Planar ceramic capacitors

Ceramic SMD capacitors are usually not marked at all except for color (I don’t know the color marking, if anyone can tell you, I’ll be glad, I only know that the lighter the capacitance, the smaller the capacity) or are marked with one or two letters and a number.

The first letter, if present, indicates the manufacturer, the second letter indicates the mantissa in accordance with the table below, the number is an exponent in base 10, to obtain the capacitance in picofarads.

Example:

N1 /from the table we determine the mantissa: N=3.3/ = 3.3*101pF = 33pF

S3 /according to table S=4.7/ = 4.7*103pF = 4700pF = 4.7nF

Sometimes Latin letter coding is used. To decipher, you should use the table of letter coding of the operating voltage.

Table of marking capacitors by operating voltage.

Planar electrolytic capacitors

Electrolytic SMD capacitors are marked in two ways:

1) Capacitance in microfarads and operating voltage, for example: 10 6.3V = 10 µF at 6.3V.

2) A letter and three digits, where the letter indicates the operating voltage according to the table below, the first two digits determine the mantissa, the last digit is the exponent in base 10, to obtain the capacitance in picofarads.

It will be interesting➡ What is the polarity of a capacitor and how to determine it?

The stripe on such capacitors indicates the positive terminal. Example: according to table “A” - voltage is 10V, 105 is 10*105 pF = 1 µF, i.e. this is a 1uF capacitor at 10V

Coded or digital marking of capacitors

Three digit capacitor coding

The first two digits indicate the capacitance value in picofarads (pf), the last two digits indicate the number of zeros. When the capacitor has a capacitance of less than 10 pF, the last digit may be "9". For capacitances less than 1.0 pF, the first digit is “0”. The letter R is used as a decimal point. For example, code 010 is 1.0 pF, code 0R5 is 0.5 pF.

* Sometimes the last zero is not indicated.

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Capacitor coding using four digits

Capacitance marking in microfarads

The letter R may be used instead of the decimal point.

Mixed alphanumeric marking of capacity, tolerance, TKE, operating voltage

Unlike the first three parameters, which are marked in accordance with standards, the operating voltage has different alphanumeric markings from different companies.

Information

In addition to alphanumeric marking of capacitors, a digital marking method with three or four digits is used according to IEC standards.

With this method of marking capacitors, the first two or three digits indicate the capacitance value in picofarads (pF), and the last digit indicates the number of zeros. When designating capacitances of less than 10 pF, the last digit may be “9” (109 = 1 pF), when designating capacitances of 1 pF or less, the first digit will be “0” (010 = 1 pF). The letter R is used as the separating comma (0 R 5 = 0.5 pF).

When marking capacitor capacities in microfarads, digital marking is used: 1 - 1 µF, 10 - 10 µF, 100 - 100 µF. If it is necessary to mark fractional capacitance values, the letter R is used as a separating comma: R 1 - 0.1 µF, R 22 - 0.22 µF, 3 R 3 - 3.3 µF (when designating capacitance in µF, the number 0 before the letter R is not put, but it is put only when designating capacitances less than 1 pF).

After the designation of the capacitance, a letter symbol may be applied indicating the permissible deviation of the capacitance of the capacitor.

The article partially used material from the following sources: Source 1 | Source 2

Some notes and tips on working with capacitors

It must be remembered that capacitors with a higher rated voltage should be selected as the ambient temperature increases, creating a larger voltage reserve to ensure high reliability. If the maximum constant operating voltage of the capacitor is specified, this refers to the maximum temperature (unless otherwise stated). Therefore, capacitors always operate with a certain margin of safety. And yet, it is desirable to ensure that their actual operating voltage is at a level of 0.5-0.6 nominal.

If a limit value for alternating voltage is specified for a capacitor, then this applies to a frequency of (50-60) Hz. For higher frequencies or in the case of pulsed signals, the operating voltages should be further reduced to avoid overheating of the devices due to dielectric losses. High-capacity capacitors with low leakage currents are able to retain the accumulated charge for a long time after the equipment is turned off. To ensure faster discharge, for greater safety, you should connect a resistor with a resistance of 1 MOhm (0.5 W) in parallel with the capacitor.

Code marking of capacitors with 3 digits

For example, a capacitor with the designation 153 means that its capacitance is 15000 pF.

Marking capacitors using a numerical-alphabetic code.

The marking of capacitors may indicate the following parameters: Type of capacitor, its rated capacity, permissible deviation of capacitance, Temperature Coefficient of Capacitance (TKE), rated operating voltage.

The order of marking may be different - the first line may be the rated voltage, TKE or the manufacturer's brand name. TKE may be absent altogether, the rated voltage is also not always indicated! There is almost always a marking of the nominal capacity. As for capacity, there are various ways to encode it symbolically. 1. Marking of the container using three numbers. With this marking, the first two digits indicate the capacitance value in picofarads, and the last one indicates the bit depth, i.e., the number of zeros that must be added to the first two digits. But if the last digit is “9”, division by 10 occurs.

2. The second option - marking is done not in pico, but in microfarads, and the letter µ is placed instead of the decimal point.

3. Third option.

Soviet capacitors used “p” instead of the Latin “r”.

The permissible deviation of the nominal capacity is marked with a letter, often the letter follows the code defining the capacity (the same line).

Further, there may be (or may not be!) marking of the Temperature Coefficient of Capacity (TKE). For capacitors with non-standardized TKE, coding is done using letters.

Capacitors with a linear dependence on temperature.

Next comes the voltage in volts, most often in the form of a regular number. For example, the capacitor in this picture is marked with two lines. The first (104J) means that its capacitance is 0.1 μF (104), the permissible deviation of the capacitance does not exceed ± 5% (J). The second (100V) is the voltage in volts.

In addition, the voltage of the capacitors can also be encoded using letters (see table below).

Alphanumeric marking of capacitors

Often, instead of just digital, alphanumeric markings are used. In this case, not only the letter itself in the code is important, but also its position. Thus, the letter R is used as a decimal point, for example, the code 0R5 (or R5) is equal to 0.5 picofarads, the code 4R7 is 4.7 picofarads.

The letters “p”, “n” and “u”, as well as their capital variants, are also used as a decimal point, but at the same time they also indicate a unit of measurement (picofarad, nanofarad, microfarad, respectively). That is, the code 5n6 means 5.6 nanofarads, n56 - 0.56 nanofarads, 5u2 - 5.2 microfarads, 4P7 - 4.7 picofarads.

Capital Latin letters after a three-digit number (or a three-digit number + unit of measurement) mean tolerance:

That is, for example, code 223J reads “22” + “000” = “22000” picofarad -> 22 nanofarad with a tolerance of ± 5%. 220nM – 220 nanofarads with ±20% tolerance.

If the code consists of five or six values, for example, 1E504K, then it needs to be divided into three parts. The first is the first number and letter indicating voltage; the second is the usual three-digit code; the third is the tolerance letter. That is, 1E504K is a capacitor with a capacity of 504 nanofarads, a rated voltage of 25 V and a tolerance of ± 10%.

Common voltage symbols

If the voltage is indicated by only one letter, then by default the number in front of it is one. For example, the marking D1622K means that the capacitance of the capacitor is 16.2 nanofarads, the tolerance is ±10%, the voltage is 20 V. The two in front of the letter means that the voltage indicated by the letter is multiplied by 10. That is, 1A = 10 V, 2A = 100 V; 1E = 25 V, 2E = 250 V.

If the marking on the capacitor looks like “letter-number-letter”, then the information concerns the operating temperatures of the device. The first letter means the minimum temperature:

Storage Features

Tantalum capacitors are able to maintain performance characteristics for a long time. If the required conditions are observed (temperature up to +40°, relative humidity 60%), the capacitor loses its ability to be soldered during long-term storage, while maintaining other performance characteristics.

General recommendations for extending the service life of a tantalum capacitor and increasing the safety of its operation:

• Compliance with technical process requirements;
• Multi-stage product quality control;
• Compliance with storage conditions;
• Fulfilling the requirements for organizing a workplace for mounting devices on a board;
• Compliance with the recommended soldering temperature conditions;
• Correct selection of safe operating modes;
• Compliance with operating requirements.