Ceramic capacitors are used in a variety of ways, serving different functions in different circuits. Typical ceramic capacitors are divided into 4 types, namely coupling, decoupling, smoothing, and filter. As a ceramic capacitors manfacturer, we will describe the above four capacitors in detail.
coupling
When the ceramic capacitor is used for the coupling function, its DC component will not pass but only its AC component will be fully utilized, and it is used when it is necessary to separate the AC component from the DC + AC component.
Since the working conditions of active components such as transistors and ICs on the circuit are different, it is necessary to set the best working conditions for each circuit before separating the required AC signal. The so-called coupling means to combine circuits. As the name implies, coupling capacitors can be used in combination between circuits.
decoupling
There are capacitance and inductance components in the power line on the circuit. Due to their influence, once the voltage fluctuation of the power line is large, the operation of the circuit will become extremely unstable. In extreme cases, power supply fluctuations can overlap on the signal lines and generate false signals.
Therefore, decoupling capacitors are used in order to guide the noise flowing from the power supply to the ground and to continuously supply a stable current against sudden changes in the load current of components such as ICs. As shown in Fig. 2, even in the state where the noise overlaps, the noise can be led to the ground part through the decoupling capacitor.
For smoothing
Smoothing capacitors are used to suppress pulses generated in the rectified power supply circuit and smooth the signal so that it is closer to DC. If a smoothing capacitor is inserted after rectification, electricity can be stored in the capacitor at high voltage and discharged at low voltage, effectively suppressing voltage fluctuations.
filter
By combining capacitors, resistors, and inductors, it is possible to create a filter that passes only signals of a specific frequency. Filters are divided into low-bypass filters that extract only low-frequency components and high-bypass filters that extract only high-frequency components, and can be used according to the desired frequency.