A ceramic capacitor refers to a fixed-value capacitor in which the ceramic material performs the role of a dielectric. Its construction takes place with multiple alternating ceramic layers as well as a metal layer. Furthermore, the metal layer performs the role of electrodes.
Introduction to Ceramic Capacitor
Ceramic capacitors are the common types of capacitors whose use takes place in many electrical instruments. This is because their production is more reliable as well as cheaper.
These capacitors involve discs of ceramic or porcelain and they exist in a non-polarized form. Furthermore, the ceramic material serves as an excellent dielectric due to its poor conductivity. Moreover, it is also an efficient supporter of the electrostatic fields.
How do we Measure Ceramic Capacitor?
The measurement of the capacitance of ceramic capacitors takes place by using measurement instruments. One of the best measurement instruments is the LCR meter.
The measurement method most commonly used with an LCR meter is known as the auto-balancing bridge method. The use of this method with LCR meters takes place by many physicists. In this method, the adjustment of current at a measured object (=DUT) and a known resistance R takes place in such a manner that both turn out to be the same.
So, the voltage at one point would become 0. Then, the LCR meter calculates the impedance of complex nature from the voltage. The application of this voltage takes place to a DUT and a known resistance R. Also, the derivation of the capacitance of ceramic capacitors takes place from the complex impedance’s reactance component.
Characteristics of Ceramic Capacitor
Accurate tolerances and precision- The use of ceramic capacitors mainly takes place for high stability performances. Here the devices are characterized by low losses. Moreover, extremely accurate results are possible due to these devices.
Advantages of small size- In cases of packing, there is a requirement for densities of high components. Furthermore, these devices are much more advantageous in comparison to the other capacitors. For example, a “0402” multi-layered ceramic capacitor can facilitate the measurement of about 0.4 mm x 0.2 mm.
High power and high voltage- The manufacturing of ceramic capacitors takes place in such a manner that they can tolerate higher voltages. Moreover, such capacitors are power ceramic capacitors. Also, these capacitors are significantly larger than the PCBs and they also have specialized terminals used for safer connection of high voltage supply due to their specialized terminals.
Ceramic Capacitors Dielectric Classes- The ceramic capacitors dielectric classes assist in the selection of the capacitors on the basis of their usage.
Formula of the Capacitance of Ceramic Capacitor
Electrical capacitance refers to the property of objects that can conduct or hold an electric charge. Furthermore, the capacitor is an electric component that comes into existence from producing a small gap between layers which carry the charge. A good example of this can be a ceramic capacitor.
The capacitance is the charge that is divided by the voltage difference across the capacitor. Furthermore, the measurement of capacitance takes place in Farads (F). Also, the measurement of charge takes place in Coulombs (C), and the measurement of voltage takes places in Volts (V).
Capacitance = electric charge/voltage drop across a capacitor
C = Q/V
C = capacitance (Farads, F)
Q = the charge built up that takes places on the capacitor (Coulombs, C)
V = voltage difference that takes place between two sides of a capacitor (Volts, V)
Derivation of the Formula of Capacitance of a Ceramic Capacitor
C = Q/V ⟶ eqn(i)
Now, we know that the expression of the E⃗ E→ between the plates of capacitors can take place as:-
⟹E⃗ = Q/Aϵo ⟶ eqn(ii)
One can consider the ΔV between the plates to be V and distance present between them to be d,
⟹V = Ed
We got the above formula by ΔV= −∫E⃗ .d⃗ and E= constant.
By inserting the value of V=Ed in eqn(i), one would get :-
⟹C = Q/Ed
⟹C = Aϵo/d from eqn (ii)
FAQs For Ceramic Capacitor
Question 1: What is meant by ceramic capacitor code?
Answer 1: There are two or three digits codes printed on ceramic disc capacitors. Furthermore, the first two numbers tell us about the value of the capacitor. Moreover, the third number is the number of zeros that exist in the multiplier.
Question 2: What are the various ceramic types?
Answer 2: The two most common types of ceramic capacitors are multi-layered ceramic capacitors and ceramic disc capacitors. Furthermore, the use of multi-layered ceramic capacitors takes place for RFI/EMI suppression systems. Moreover, the use of ceramic disc capacitors takes place in safety capacitors in electromagnetic interference suppression applications.