SMD capacitors can generally be divided into four categories: NP0 capacitors, X7R capacitors, Z5U capacitors, Y5V capacitors
The main difference between NP0, X7R, Z5U and Y5V is their filling medium. Under the same volume, the capacity of the capacitor formed by the different filling medium is different, and the dielectric loss and capacity stability of the capacitor are also different.
NP0 capacitor
NP0 is one of the most commonly used monolithic ceramic capacitors with temperature compensation. Its filling medium is composed of rubidium, samarium and some other rare oxides.
NP0 capacitors are one of the most stable capacitors in terms of capacitance and dielectric loss. When the temperature is from -55℃ to 125℃, the capacity change is 0±30ppm/℃, and the capacitance change with frequency is less than ±0.3℃. The drift or hysteresis of NP0 capacitors is less than ±0.05%, which is negligible compared to film capacitors greater than ±2%. Its typical capacity versus lifetime variation is less than ±0.1%. NP0 capacitors have different characteristics of capacitance and dielectric loss with frequency depending on the package form. Larger package size has better frequency characteristics than small package size.
NP0 capacitors are suitable for tank capacitors in oscillators, resonators, and coupling capacitors in high frequency circuits.
X7R capacitors
X7R capacitors are called temperature-stable ceramic capacitors. When the temperature is from -55°C to 125°C, the capacitance change is 15%. It should be noted that the capacitance change of the capacitor is non-linear at this time.
The capacity of the X7R capacitor is different under different voltage and frequency conditions, it also changes with time, about 1% every 10 years, and it shows about 5% change in 10 years.
X7R capacitors are mainly used in less demanding industrial applications where the change in capacitance when the voltage changes is acceptable. Its main feature is that the capacitance can be relatively large under the same volume. The following table shows the available capacity range of X7R capacitors.
Z5U capacitor
Z5U capacitors are called "universal" ceramic monolithic capacitors. The first thing to consider here is the operating temperature range, the main thing for the Z5U capacitor is its small size and low cost. For the above three ceramic monolithic capacitors, the Z5U capacitor has the largest capacitance under the same volume. However, its capacitance is greatly affected by environmental and working conditions, and its aging rate can decrease by up to 5% every 10 years.
Despite its unstable capacity, it has a wide range of applications due to its small size, low equivalent series inductance (ESL) and equivalent series resistance (ESR), and good frequency response. Especially in decoupling circuit applications. The table below shows the range of values for Z5U capacitors. Z5U capacitor operating temperature range 10℃ --- 85℃, temperature characteristics 22% ---- -56% dielectric loss maximum 4%
Y5V capacitor
The Y5V capacitor is a general-purpose capacitor with a certain temperature limit, and its capacitance can vary from 22% to -82% in the range of -30°C to 85°C. The high dielectric constant of Y5V allows the fabrication of capacitors up to 4.7µF in a small physical size. Operating temperature range of Y5V capacitor -30℃ --- 85℃, temperature characteristic 22% ---- -82%, dielectric loss max. 5%