Ceramic Capacitor Value Vs Voltage

Typical voltage coefficient of capacitance.

Ceramic capacitor value vs voltage.

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. Rohm has experimented with both film and ceramic capacitors for its sic power transistor snubbers. Dc voltage for select 4 7µf capacitors. Ceramic capacitor ir and dcl.

Ceramic disc capacitor code label will normally consist of three numbers followed by a letter. 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. Mlcc 0 0 8 1 6 2 4 3 2 4 1 0 0 6 0 4 0 8 0 2 dc volts applied 298d 47 μf mlcc 47 μf mlcc 100 μf. As capacitance values and hence the area of dielectric increases the ir decreases.

They are very easy to decode to find the value. 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. In ceramic capacitors can also be caused by ac voltage. A ceramic capacitor is a fixed value capacitor where the ceramic material acts as the dielectric it is constructed of two or more alternating layers of ceramic and a metal layer acting as the electrodes the composition of the ceramic material defines the electrical behavior and therefore applications.

The third digit is the multiplier which is 1000. Excerpting from the kemet page you link to in this article. One thing to keep in mind is that ceramic capacitors will lose their capacitance value as the voltage approaches. Insulation resistance is the resistance measured across the dielectric of a capacitor.

However the rule of thumb dictates that you should derate ceramic capacitors by 50 which means that if you are expecting to have a maximum of 5v between the capacitor s leads then you should use a capacitor rated for 10v or more. The first two significant digits represent the first two digits of the actual value which is 47. 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. These 10 capacitors give the voltage rating and value commensurate with a single film capacitor.

Depending on the dielectric formulation these capacitors can lose more than 70 of its rated capacitance with applied. Capacitance change over time for class 2 x7r and x5r dielectric capacitors. This does not happen with class 2 mlcc capacitors.