Types and Characteristics of Patch Capacitors(I)

Types and characteristics of patch capacitors

Monolithic ceramic capacitors (commonly referred to as patch capacitors) are commonly used components with relatively large consumption at present. There are different specifications such as NPO, X7R, Z5U, Y5V and so on for the patch capacitors produced by AVX Company. Different specifications have different uses. Below we will only introduce the performance and application of NPO, X7R, Z5U and Y5V, as well as the order items we should pay attention to in order to attract your attention. Different companies may have different naming methods for capacitors with different properties above. Here we refer to AVX's naming method. For other companies, please refer to the company's product manual.

The main difference between NPO, X7R, Z5U and Y5V is that their filling media are different. Under the same volume, the capacitance of capacitors made up of different filled media is different, and the dielectric loss and capacity stability of the capacitors are also different. Therefore, when using capacitors, different capacitors should be selected according to the function of capacitors in the circuit.

(I )NPO capacitor

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 capacitor is one of the most stable capacitors with the most stable capacitance and dielectric loss. When the temperature is from -55 ℃ to + 125 ℃, the capacity changes to 0 ±30ppm/ ℃, and the change of capacitance with frequency is less than ±0. 3 Δ C. The drift or hysteresis of NPO capacitor is less than ±0.05, which is negligible when the capacitance is larger than ±2%. The variation of typical capacity relative to service life is less than ±0.1%. The capacitance and dielectric loss of NPO capacitors vary with frequency according to the packaging form. The frequency characteristics of large package size are better than that of small package size. The following table shows the range of capacities that can be selected for NPO capacitors.

Seal DC=50V DC=100V

0805 0.5---1000pF 0.5---820pF

1206 0.5---1200pF 0.5---1800pF

1210 560---5600pF 560---2700pF

2225 1000pF---0.033μF 1000pF---0.018μF

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