As the name suggests, the ‘Ceramic capacitor’ uses ceramic as the dielectric material. They are also known as Disc Capacitors. They are manufactured by using a ceramic or porcelain disc coated on its both faces by a thin layer of Silver.
It is the arrangement and property of the ceramic substance which characterize the functional aspects of the Ceramic capacitor. They are broadly classified into three basic classes. The lower is the class, the superior it is in terms of performance. These three classes are:
- Class I – This class of Ceramic capacitors provide more stability in capacitance value w.r.t. change in temperature.
- Class II – This type of Ceramic capacitor provide more efficiency in terms of size. They are best suitable for use as decoupling capacitor or as buffer.
- Class III – They are almost same as Class II ceramic capacitors. However, They lack in accuracy and are not stable as Class II in terms of change in temperature.
The various properties of Ceramic capacitors are as follows :
- Dielectric Constant (K) – They possess a large dielectric constant (K). This property allows the Ceramic capacitor to provide a high capacitance value even in its small sizes.
- Effect on Capacitance with change in temperature – The capacitance of Ceramic capacitor changes non linearly with change in temperature. For this reason, they are best suitable for use as Decoupling capacitor or Bypass capacitors.
- Polarization – Ceramic capacitor is non polarized. That means that there is no polarity issue with this type of capacitors. They can be connected to the circuit from any side.
- Cost – There manufacturing cost is very low.
- Size – They are available in small sizes. It is therefore, space for this in a circuit is not a matter of concern.
- Reliability – They are very reliable and possess high tolerance value. The chances of damage is also less.
- Capacitance range – They are available in various capacitance value ranging from a few pF to 1/2 µF.
- Voltage rating – They have normally a low voltage rating.
This type of capacitors is used normally in various circuits such as audio, RF, by pass and decoupling etc.