There is a corresponding relationship between the stability and capacity accuracy of chip capacitors and the dielectric materials used, which are mainly divided into three categories:
1. It is a high-frequency capacitor with COG/NPO as the Class I medium. Its temperature coefficient is ±30ppm/℃, and its capacitance is very stable. It hardly changes with changes in temperature, voltage and time. It is mainly used in high-frequency electronic circuits. Such as oscillation, timing circuit, etc.; its capacity accuracy is mainly ±5, and when the capacity is less than 10pF, it can choose B file (±0.1pF), C file (±0.25pF), D file (±0.5pF) Accuracy.
2. It is an intermediate frequency capacitor with X7R as the type II medium. Its temperature coefficient is ±15, and its capacitance is relatively stable. It is suitable for various bypass, coupling, and filter circuits, and its capacity accuracy is mainly K gear (±10).
Under special circumstances, products with J-level (±5) accuracy can be provided.
Different types of capacitors use different frequencies. Small mica capacitors are within 250MHZ; disc type ceramic capacitors are 300MHZ; round tube type ceramic capacitors are 200MHZ; disc type ceramic capacitors can reach 3000MHZ; small paper capacitors are 80MHZ; medium paper capacitors are only 8MHZ.
3. It is a low-frequency capacitor with Y5V as the type II medium. Its temperature coefficient is +30～-80. The capacitance varies greatly by temperature, voltage and time, and it is generally only suitable for various filter circuits. Its capacity accuracy is mainly in Z range (+80～-20), and products with ±20 accuracy can also be selected.
The chip resistor has problems in the circuit. It may be the poor quality of the chip capacitor itself, or it may be caused by factors such as poor specifications during the design or mechanical thermal shock on the surface. cause.
When choosing a chip capacitor correctly, in addition to providing its specifications, size and capacity, you must also pay special attention to the circuit's requirements for the temperature coefficient, rated voltage and other parameters of the chip capacitor. Standard naming method and definition of chip capacitors: The naming of chip capacitors has a difference between domestic and foreign manufacturers, but the parameters included are the same