What is the role of ceramic capacitors in signal circuits?

The main function of ceramic capacitors used in power circuits is to complete coupling, oscillation/synchronization, and time constant
Capacitors, abbreviated as capacitors, are represented by the letter C. The international unit is Farad, abbreviated as Farad, and represented by F. In practical applications, the capacitance of capacitors is often much smaller than 1 Farad, and smaller units such as microfarads are commonly used( μ F) Skin method (pF), etc. Capacitors can generally be divided into polar capacitors and non-polar capacitors.

Ceramic capacitors are generally non-polar capacitors with a capacity value generally less than 1 μ F. For example, the commonly used ceramic capacitor is 0.1UF (104).

What is the role of ceramic capacitors in signal circuits?

1. Time constant

This is a common integral circuit composed of R and C series connection. When the input signal voltage is applied to the input terminal, the voltage on the capacitor (C) gradually increases. And its charging current decreases with the increase of voltage. The characteristics of current passing through resistance (R) and capacitance (C) are described by the following formula:

I=(V/R) e - (t/CR)

2. Oscillation/synchronization

This includes RC, LC oscillators, and crystal load capacitors.

What is the role of ceramic capacitors in signal circuits

3. Coupling

For example, a transistor amplifier has a self-sufficient bias resistor at the emitter, which also generates voltage drop feedback to the input terminal, forming input output signal coupling. This resistor is the component that generates coupling. If a capacitor is connected in parallel at both ends of this resistor, the appropriate capacity of the capacitor reduces the impedance of the AC signal, thus reducing the coupling effect caused by the resistor, Therefore, this capacitor is called a decoupling capacitor.

4. Time constant

This is a common integral circuit composed of R and C series connection. When the input signal voltage is applied to the input terminal, the voltage on the capacitor (C) gradually increases. And its charging current decreases with the increase of voltage. The characteristics of current passing through resistance (R) and capacitance (C) are described by the following formula:

I=(V/R) e - (t/CR)