The X5R, X7R, Y5V, Z5U, COG, COH and other parameters of the chip capacitor describe the type of dielectric material used by the capacitor, temperature characteristics and error parameters, different values also correspond to a certain range of capacitance capacity, what are the differences? Let's talk about each of them.

High-frequency class: The capacitors of such dielectric materials are Class I capacitors, including general high-frequency COG, COH capacitors and temperature-compensated high-frequency HG, LG, PH, RH, SH, TH, UJ, SL capacitors. Among them COG, COH capacitor electrical performance is the most stable, almost does not change with the temperature, voltage and time changes, suitable for low loss, stability requirements of high frequency circuit, HG, LG, PH, RH, SH, TH, UJ, SL capacitor capacity changes with the temperature changes, suitable for low loss, temperature compensation circuit.

X7R, X5R, X7S, X6S: capacitors of this kind of dielectric material are Class II capacitors, with higher dielectric constant, higher capacity than class I capacitors, with more stable temperature characteristics, suitable for a wide range of capacity, stability requirements are not high in the circuit, such as straight separation, coupling, bypass, frequency discrimination and other circuits.

Y5V: The capacitor of this kind of dielectric material is Class II capacitor, which is the largest intermediate electrical constant of all capacitors, but its capacity stability is poor, and it is more sensitive to temperature, voltage and other conditions, and is suitable for circuits requiring large capacity and little temperature change.

Z5U: capacitors of this kind of dielectric material are Class II capacitors, whose temperature characteristics are between X7R and Y5V, poor capacity stability, more sensitive to temperature, voltage and other conditions, suitable for large capacity, the use of temperature range close to room temperature bypass, coupling, etc., low DC bias circuit.

Characteristics of Class I ceramics:

Class I ceramic capacitor (formerly known as High-frequency ceramic capacitor), the medium is non-ferroelectric (paraelectric) formula, with TiO2 as the main component (dielectric constant less than 150), Therefore it has the most stable performance; Alternatively, by adding a small amount of other (ferroelectric) oxides, such as CaTiO3 or SrTiO3, to form an "extended" temperature compensation ceramic, the temperature coefficient can be approximately linear, and the dielectric constant can be increased to 500. These two media have low loss, high insulation resistance and good temperature characteristics. It is especially suitable for oscillators, resonant circuits, coupling capacitors in high-frequency circuits, and other circuits requiring low loss and stable capacitance, or for temperature compensation.

Temperature characteristics of Class I ceramics:

The temperature capacity characteristic (TCC) of Class I ceramics is very small, often in ppm/℃, and the change in capacity from the reference value is often much less than that of the 1 skin method. The Electronic Industry Association (EIA) standard uses the code form of "letter + number + letter" to represent the temperature coefficient of Class I ceramics. Such as the common C0G.

What is the temperature coefficient of C0G?

C indicates that the effective number of the capacitance temperature coefficient is 0ppm/℃

0 means that the multiplier of a significant number is -1 (i.e. 10 to the power of 0).

G indicates a tolerance of ±30ppm with temperature

Calculated, the final TCC of the C0G capacitor is: 0× (-1) ppm/℃±30ppm/℃. The corresponding temperature coefficient of other Class I ceramics, such as the U2J capacitance, is calculated as: -750 ppm/℃±120 ppm/℃.

The relationship between NPO and C0G:

NPO is the term in the United States Military Standard (MIL), which should actually be NP0 (zero), but it is generally used to write NPO (European). This is short for Negative-Positive-Zero, which is the temperature characteristic. It shows that the capacitance temperature of NPO is very good, and the capacitance drift does not occur with the change of positive and negative temperature.

As we already know from the previous, C0G is one of the best temperature stability in Class I ceramics, and the temperature characteristic is approximately 0, meeting the meaning of "negative - positive - zero". So C0G is actually the same as NPO, but it is two representations of two standards (of course, C0K, C0J, etc. with smaller capacity and slightly less precision are also NPO capacitors). Similarly, U2J corresponds to the group code N750 in the MIL standard.

NPO is one of the most commonly used monolithic ceramic capacitors with temperature compensation characteristics. Its filling medium is composed of rubidium, samarium and some other rare oxides.

NPO capacitors are one of the most stable capacitors in terms of capacitance and dielectric loss. At temperatures from -55 ° C to +125 ° C, the capacitance changes by 0±30ppm/ ° C, and the capacitance changes with frequency by less than ±0.3ΔC. The drift or lag of NPO capacitors is less than ±0.05%, which is negligible compared to thin film capacitors greater than ±2%. The typical variation in capacity relative to service life is less than ±0.1%. The capacitance and dielectric loss of NPO capacitors vary with frequency depending on the package form, and the frequency characteristics of large package size are better than that of small package size. The following table shows the optional capacity range of NPO capacitors.

NPO capacitors are suitable for slot capacitors in oscillators, resonators, and coupling capacitors in high-frequency circuits.

Class II ceramics features:

Class II ceramic capacitor (Class II ceramic capacitor) used to be called Low frequency ceramic capacitor (Low frequency ceramic capacitor), refers to the capacitor using ferroelectric ceramics as a medium, so it is also known as ferroelectric ceramic capacitor. The specific capacitance of this type of capacitor is large, the capacitance changes nonlinear with temperature, and the loss is large, and it is often used in electronic equipment for bypass, coupling or other circuits with low requirements for loss and capacitance stability. Class II ceramic capacitors are divided into stable stage and usable stage. X5R and X7R belong to the stable level of Class II ceramics, while Y5V and Z5U belong to the usable level.

The difference between X5R, X7R, Y5V, Z5U:

The difference mainly lies in the temperature range and the variation characteristics of the capacity with temperature. The following table indicates the meanings of these code names.

Take the X7R for example.

X means that the capacitor can work at a minimum of -55 ° C

7 means the capacitor can operate at a maximum of +125 ° C

R means that the change in volume with temperature is ±15%

Similarly, the normal operating temperature range of Y5V is -30℃ ~ +85℃, and the corresponding capacitance change is +22 ~ -82%; The normal operating temperature range of Z5U is +10℃ ~ +85℃, and the corresponding capacitance change is +22 ~ -56%.

The X7R capacitor is known as a temperature-stable ceramic capacitor. When the temperature is -55 ° C to +125 ° C, the capacity change is 15%, it should be noted that the capacitor capacity change is non-linear at this time.

The capacity of the X7R capacitor is different under different voltage and frequency conditions, and it also changes with time, changing about 1%ΔC every 10 years, showing a change of about 5% over 10 years.

X7R capacitors are mainly used in less demanding industrial applications where the capacity change is acceptable when the voltage changes. Its main feature is that the power capacity can be relatively large under the same volume.

The value range of X7R/X7S/X5R/X6S capacitors is shown in the following table (the value range varies slightly according to the manufacturer):

The Y5V capacitor is a general purpose capacitor with a certain temperature limit, and its capacity can vary from +22% to -82% in the range of -30 ° C to 85 ° C.

Y5V's high dielectric constant allows capacitors up to 4.7µF to be manufactured at small physical sizes.

Other technical indicators of Y5V capacitors are as follows: Operating temperature range -30℃ ~ +85℃ Temperature characteristics +22% ~ -82% Dielectric loss maximum 5%

Z5U capacitors are called "universal" ceramic monolithic capacitors. The first thing to consider here is the use of temperature range, the main thing for Z5U capacitors is its small size and low cost. For the above three ceramic monolithic capacitors, the Z5U capacitor has the largest capacitance in the same volume. However, its electrical capacity is greatly affected by the environment and working conditions, and its aging rate can decrease by up to 5% every 10 years.

Despite its capacity instability, due to its small volume, low equivalent series inductance (ESL) and equivalent series resistance (ESR), good frequency response, so that despite its capacity instability, due to its small volume, low equivalent series inductance (ESL) and equivalent series resistance (ESR), good frequency response, it has a wide range of applications. Especially in the application of decoupling circuits.

Other technical indicators of Z5U capacitors are as follows: Operating temperature range +10℃ ~ +85℃ Temperature characteristics +22% ~ -56% Dielectric loss maximum 4%.

The value range of COG/NPO/Y5V/Z5U capacitors is shown in the following table (there are slight differences in the value range of different manufacturers):

The chip resistance has problems on the circuit, which may be caused by the poor quality of the chip capacitor itself, or the design specification is not good, or the surface mount mechanical thermal shock and other factors that cause certain damage to the chip capacitor.

When selecting a chip capacitor correctly, in addition to providing its size and capacity, special attention must be paid to the circuit's requirements for the temperature coefficient, rated voltage and other parameters of the chip capacitor. Standard naming method and definition of chip capacitors: The naming of chip capacitors, domestic and foreign manufacturers have some differences but the parameters contained are the same.