Types and Characteristics of Patch Capacitors(I)

Monolithic ceramic capacitors (commonly known as patch capacitors) are commonly used components with relatively large consumption at present. According to the patch capacitors produced by AVX Company, they have different specifications such as NPO, X7R, Z5U, Y5V, etc. Different specifications have different uses. Below we will only introduce their properties and applications and the order items that should be noted in the purchase of NPO, X7R, Z5U and Y5V in order to attract your attention. Capacitors with different properties may have different naming methods, Here we refer to AVX's naming method. For other company's products, please refer to the company's product manual.

The main difference between NPO, X7R, Z5U and Y5V is that their filling media are different. As a result, the dielectric loss and capacity stability of capacitors are different, so different capacitors should be chosen according to the function of capacitors in the circuit.

A NPO capacitor.

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

NPO capacitor is one of the most stable capacitors with capacitance and dielectric loss. The capacity varies to 0 ±30ppm/ ℃ at temperatures ranging from -55 ℃ to + 125 ℃. The change of capacitance with frequency is less than ±0. 3 Δ C.NPO capacitance drift or lag less than ±0. 05, and relative greater than ±2% thin film capacitance can be ignored. Its typical capacity relative service life change is less than ±0.1%.NPO capacitor with packaging form. The characteristics of the variation of capacitance and dielectric loss with frequency are different. The frequency characteristic of large package size is better than that of small package size. The capacity range of NPO capacitor is given in the following table.

Sealing 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---0.033 μ F 1000pF---0.018 μ F.

NPO capacitors are suitable for oscillator, resonator slot capacitors and coupling capacitors in high frequency circuits.