one important parameters of the capacitor
1.the capacitance (C: capacitance)
The basic characteristic of a capacitor is the ability to store charge, and the amount of charge stored (Q) is proportional to the electrical capacity (C) and the applied voltage (V).
I.e., Q = CV
Units of electrical capacity: 1 farad =103 millifarad =106 microfarad =109 nanofarad (nanofarad) =1012 leather =1015 flyer
Factors influencing electric capacity: C=KA/ft (A:L*W)
K: is the dielectric constant
F: is the conversion factor f=113.1mm
T: is the thickness of capacitance
C: picofarad (pico method)
Dielectric constant (k) value: it depends on the ceramic material in which the capacitor is filled.The ambient temperature, working voltage and frequency, and the working time (long-term stability) of the capacitor have different effects on different media.Generally, the higher the dielectric constant (k) value, the worse the stability, reliability and durability.At present, the most commonly used ceramic capacitor media have three types: COG or NPO,K value is 10-100;X7R is a stable material with a K value of 2000-4000.Y5V or Z5U is a general purpose material with a K value of 5,000-25,000.There are two kinds of pottery and porcelain in China, i. and II.COG or NPO in the above materials are super stable materials.The capacitance change of capacitors within the range of -55-+125 does not exceed 30ppm/.