Different Ceramic Capacitor Formulations

C0g np0 is the most popular formulation of the temperature compensating eia class i ceramic materials.

Different ceramic capacitor formulations.

The z5u tempco is about the least stable of the ceramic formulations. The values of the ceramic capacitors are typically between the 1nf and 1µf and the values are up to 100µf are possible. Modern c0g np0 formulations contain neodymium samarium and other rare earth oxides. A ceramic capacitor ceramic capacitors are typically referred to as disc capacitors they re made by taking a small ceramic or porcelain disc and coating both sides with silver before stacking them together to make a functioning capacitor.

Thus c0g capacitors remain constant with time. C0g np0 ceramics offer one of the most stable capacitor dielectrics available. The decline in capacitance is called aging and occurs at a rate that decreases roughly linearly with the log of time. Based on the type of the material used the ceramic capacitor is classified as class1 class2 class3.

I discussed reliability issues with an engineers from. Capacitance change with temperature is 0 30ppm c which is less than 0 3 c from 55 c to 125 c. These have poor temperature and voltage coefficients. Class 1 ceramic capacitors offer high stability and low losses for resonant circuit applications.

The class2 capacitors which uses ferroelectric material is more preferred nowadays compared to the class1 capacitors which uses a paraelectric material. The multilayer ceramic capacitors are prepared by using the surface mounted smd technology and they are smaller in size therefore it is used widely. Class3 uses a semiconductor material which is hardly in use nowadays. The two common types of ceramic capacitors are multilayer ceramic capacitor mlcc and ceramic disc capacitor.

Class 2 ceramic capacitors offer high volumetric efficiency for buffer by pass and coupling applications. Due to its low permittivity c0g ceramic capacitors have low capacitance. C0g also commonly known as np0 is an ultra stable dielectric material. This ceramic dielectric material has low relative permittivity.

Rmc was a popular brand years ago and made lots and lots of different kinds of caps. Manufacturers use different formulations to produce c0g since the eia classification does not define the material. Interestingly the c0g capacitors have a different formulation which does not display any aging characteristic. I ve done laboratory testing of ceramic capacitor for microphonics and found that you need to really smack them with high impact.

Ceramic capacitors are divided into two application classes. Single ceramic discs of around 3 6mm are used when low capacitance values are needed.