NPO capacitors and X7R capacitors

NPO capacitors and X7R capacitors

NPO is one of the most commonly used monolithic ceramic capacitors with temperature compensation characteristics. Its filling medium is composed of rubidium, samarium and some other rare oxides. NPO capacitors are one of the most stable capacitors in capacitance and dielectric loss. When the temperature is from -55℃ to +125℃, the capacity change is 0±30ppm/℃, and the change of capacitance with frequency is less than ±0.3ΔC. The drift or hysteresis of NPO capacitors is less than ±0.05%, which is negligible relative to film capacitors greater than ±2%. The variation of its typical capacity relative to the service life is less than ±0.1%. NPO capacitors have different characteristics of capacitance and dielectric loss with frequency depending on the package type. Large package size has better frequency characteristics than small package size. NPO capacitors are suitable for tank circuit capacitors of oscillators and resonators, and Coupling capacitors in high frequency circuits. X7R capacitors are called temperature-stable ceramic capacitors. When the temperature is between -55℃ and +125℃, its capacity change is 15%. It should be noted that the change of capacitor capacity is nonlinear at this time.

The capacity of the X7R capacitor is different under different voltage and frequency conditions, and it also changes with time, about 1%ΔC changes every 10 years, which is about 5% change in 10 years.

X7R capacitors are mainly used in low-demand industrial applications, and when the voltage changes, the capacity change is acceptable. Its main feature is that the capacitance can be made relatively large under the same volume.

Summary: X7R is less stable than NPO, but the capacity is higher than that of NPO, and the capacity accuracy is about 10%. X7R capacitors are mainly used in low-demand industrial applications, and when the voltage changes, the capacity change is acceptable. Its main feature is that the capacitance can be made relatively large under the same volume.