The Precision Representation Method of Chip Capacitors 3

There is also a color code method, which has the same meaning as the marking method of domestic capacitors.

3. Main characteristic parameters of capacitors:

(1) Capacity and error: The maximum allowable deviation range between actual capacitance and nominal capacitance. Generally divided into three levels: Level I ± 5%, Level II ± 10%, and Level III ± 20%. In some cases, there is still level 0 with an error of ± 20%.  diode

The allowable error of precision capacitors is relatively small, while the error of electrolytic capacitors is relatively large, and they adopt different error levels.

The accuracy level of commonly used capacitors and the representation method of resistors are the same. Represented by letters: D-005 level - ± 0.5%; F-01 level - ± 1%; G-02 level - ± 2%; J - Level I - ± 5%; K - Level II - ± 10%; M - Level III - ± 20%.

(2) Rated operating voltage: The maximum direct current voltage that a capacitor can withstand in a circuit for long-term stable and reliable operation, also known as withstand voltage. For devices with the same structure, medium, and capacity, the higher the withstand voltage, the larger the volume.

(3) Temperature coefficient: The relative change in capacitance for every 1 ℃ change in temperature within a certain temperature range. The smaller the temperature coefficient, the better.

(4) Insulation resistance: Used to indicate the magnitude of leakage. Generally, capacitors with small capacity have high insulation resistance, ranging from several hundred megaohms to several thousand megaohms. The insulation resistance of electrolytic capacitors is generally small. Relatively speaking, the higher the insulation resistance, the better and the smaller the leakage.

(5) Loss: The energy consumed by a capacitor in a unit of time due to the heat generated by an electric field. These losses mainly come from dielectric losses and metal losses. Usually expressed as the tangent of the loss angle.  diode

(6) Frequency characteristic: The property of the electrical parameters of a capacitor changing with the frequency of the electric field. Capacitors operating under high-frequency conditions have a smaller dielectric constant at high frequencies compared to low frequencies, resulting in a corresponding decrease in capacitance. The loss also increases with the increase of frequency. In addition, during high-frequency operation, the distributed parameters of capacitors, such as pole resistance, resistance between leads and poles, self inductance of poles, and lead inductance, can all affect the performance of capacitors. All of these limit the frequency of use of capacitors.  diode

Different types of capacitors have different maximum usage frequencies. Small mica capacitors within 250MHz; The circular ceramic capacitor has a frequency of 300MHz; The circular ceramic capacitor has a frequency of 200MHz; The disc-shaped ceramic can reach 3000MHz; Small paper capacitors have a frequency of 80MHz; Medium sized paper capacitors have a frequency of only 8MHz.