Ceramic Capacitance Voltage

The numbers are approximate at best.

Ceramic capacitance voltage.

A second letter will be a temperature coefficient if it s present. Capacitance of ceramic capacitors may also change with applied voltage. 2a is a 100vdc rating according to the eia electronic industries alliance standard. Dc voltage for select 4 7µf capacitors.

Multi layer ceramic capacitor mlcc mlccs are manufactured by accurately mixing finely ground granules of paraelectric and ferroelectric materials and alternatively layering the mix with metal contacts. The thickness of the ceramic layers in the capacitors is often very thin but dependent upon the material and the working voltage required. Both dc and ac voltage go through more or less similar contortions. The capacitance is often described in the product description as nominal value please note that among ceramic capacitors the capacitance especially of capacitors classified as high dielectric constant b x5r r x7r characteristic may differ from the nominal value when a dc voltage is applied.

Generally capacitance of ceramic tantalum film capacitors is expressed in pico farad. So capacitance on these capacitors is represented using short hand notation. If a capacitor is marked with 2a474j the capacitance is decoded as described above the two first signs is the voltage rating and can be decoded from the table given below here. This effect is more prevalent in class 2 ceramic capacitors.

Ceramic disc capacitors have a capacitance value of 10pf to 100μf with a wide variety of voltage ratings between 16 volts to 15 kv and more. Ceramic capacitors have very small area to print the value of capacitance. As an example for low voltage capacitors can be as thin as 5µm but this is often limited by the grain size of the ceramic material. The table below shows what happens to capacitance when dc voltage is applied to various ceramics.

There are several types of ceramic capacitor that can be obtained. Note first that as the package size increases the capacitance variation with applied dc voltage decreases and substantially. A second interesting point is that within a package size and ceramic type the voltage rating of the capacitors seems often to have no effect. The higher the applied voltage the lower the permittivity.

Capacitance measured or applied with higher voltage can drop to values of 80 of the value. If the capacitor has two numerical values. Ac voltage and d. The ferroelectric material depends on the applied voltage.