Advantages of Ceramic Capacitor | Disadvantages of Ceramic Capacitor
This page covers advantages and disadvantages of Ceramic Capacitor and its basics. It mentions benefits or advantages of Ceramic Capacitor and drawbacks or disadvantages of Ceramic Capacitor.
What is Ceramic Capacitor?
The capacitor which uses ceramic material as dielectric is known as ceramic capacitor. There are two main types of ceramic capacitor based on their construction viz. multi layer ceramic capacitor (MLCC) and ceramic disc capacitors. They are available with small values from 1 nF to 1 µF. Ceramic capacitors with values up to 100 µF are also possible to design. They are available in small sizes and with low maximum rated voltage.
Ceramic capacitors are not polarized and hence can be connected to AC supply. They offer good frequency response due to its low parasitic effects. These capacitors are used for bypass and decoupling applications.
As shown in the figure, disc type of ceramic capacitor has two conductive discs on both the side of ceramic insulator. Leads are attached to both of these plates which are coated with coating of waterproof ceramic composition. This type of ceramic capacitors are available up to value of 0.01 µF. They withstand DC voltages up to 750 V and AC voltages upto 350 V.
MLCC type of ceramic capacitors consist of multiple layers of ceramic material (such as barium titanate) separated by metal electrodes. This construction form many capacitors in parallel. MLCC composed of hundreds of ceramic layers with each functions as single ceramic capacitor. MLCC type consists of 500 layers or more. MLCC are available with values less than 1 µF and also in 10 to 100 pF range. They withstand voltage rating of 50 Volts or less. MLCC type of ceramic capacitors are used for high frequency filters.
The table mentions tolerance values of disc ceramic capacitor as shown in figure-2. Example 104K represents value of 10 x 104 pF which equals 100 nF with tolerance of +/-10% as per code "K" marked.
The ceramic capacitors are categorized into class-1 and class-2 based on applications of use. Class-1 are used for higher stability and low losses requirements. Class-2 are used for high capacitance per volume requirements.
Benefits or advantages of Ceramic Capacitor
Following are the benefits or advantages of Ceramic Capacitor:
➨They are reliable due to good frequency response characteristics even at higher operating frequency.
➨They withstand higher voltages up to 100 V.
➨They are lighter in weight.
➨They are inexpensive in cost.
➨They are available in various shapes and sizes.
➨They offer low ESR (Effective Series Resistance) and low ESL (Effective Series Inductance).
Drawbacks or disadvantages of Ceramic Capacitor
Following are the drawbacks or disadvantages of Ceramic Capacitor:
➨Higher capacitor values are not feasible to achieve with its construction. Capacitance values are limited to about 150 µF.
➨Higher voltage ceramic capacitors with above constructions are not available. Power ceramic capacitors are designed with larger physical shapes and sizes. They withstand higher voltages from 2 KV to 100 KV.
➨They have larger temperature coefficient.
➨Ceramic capacitors have higher tolerance values.
➨Some power supply circuits are not stable with ceramic as output capacitors.
➨Larger size capacitors lead to cracks with PCB flexing. Hence several smaller units are used in parallel.