1. What is a ceramic capacitor
Ceramic capacitors are made by extruding high dielectric constant capacitor ceramic barium titanate and titanium oxide into round tubes, discs or discs as the medium, and plating silver on the ceramics as electrodes by the sintering method. It is divided into two kinds of high-frequency porcelain and low-frequency porcelain. Capacitors with a small positive temperature coefficient of capacitance are used in highly stable oscillation circuits as loop capacitors and pad capacitors. Low-frequency ceramic capacitors are limited to bypass or DC blocking in circuits with lower operating frequencies, or occasions (including high frequencies) that do not require high stability and loss. Such capacitors should not be used in pulsed circuits because they are prone to breakdown by pulsed voltages.
2. How to classify ceramic capacitors
1. According to the dielectric material, it can be divided into: high dielectric constant capacitors and low dielectric constant capacitors.
2. According to the working frequency, it can be divided into: high-frequency ceramic capacitors and low-frequency ceramic capacitors.
3. According to the working voltage, it can be divided into: high-voltage ceramic capacitors (above 1KVDC) and low-voltage ceramic capacitors (below 500VDC).
4. According to the shape and structure, it can be divided into: disc shape, tube shape, through-center type, cylindrical shape and laminated type, etc.
5. According to the ceramic capacitors and dielectrics, it is divided into: Class I ceramic capacitors, Class II ceramic capacitors, and Class III ceramic capacitors.
Class I ceramic capacitors: NP0, SL0, C0G. Class I ceramic capacitors have very good capacitance stability, and basically do not change with temperature, voltage, time, etc., but generally the capacitance is very small.
Class II ceramic capacitors: X7R, X5R, Y5U, Y5V, 2X1. Type II ceramic capacitors have poor capacity stability, and vary greatly with temperature, voltage, and time, so they are generally used in applications that do not require high capacity stability, such as filtering.
Class III ceramic capacitors: Y5V, 2F4, ceramic capacitors EIA RS-198.