What is the high frequency characteristic of the capacitor?

First, the high frequency low frequencies are relative. If the frequency is too high, then it does not make sense for the capacity of the capacitor to become larger. Because, as we all know, the coil is an inductor that blocks high frequencies. The higher the frequency, the greater the blocking effect. Although the inductance is small, large-capacity capacitors generally have longer pins and larger plates. At this time, the equivalent inductance of the two legs of the capacitor has already greatly hindered the high frequency. Acted.

The frequency characteristic of the capacitor refers to the relationship between the capacitance of the capacitor and the like as a function of frequency. When the capacitor is operated at high frequency, as the working frequency increases, the dielectric capacity will decrease due to the decrease of the dielectric constant of the dielectric, and the loss will increase, and the distribution parameters of the capacitor will be affected, and the sensitivity will gradually appear. . In order to ensure the stability of the capacitor, the limit operating frequency of the capacitor should generally be chosen to be 1/3~1/2 of the natural resonant frequency of the capacitor.

 Therefore, high-frequency does not easily pass large-capacity electrolytic capacitors with poor high-frequency performance, while chip-shaped ceramic capacitors have an advantage in price performance.

In the same way, is the larger the inductance, the greater the hindrance to the high frequency? No. In order to obtain a large amount of inductance, it is necessary to have as many coils as possible and as large as possible, and these conductors are directed to the infinite number of plates of the capacitor, if it happens that the distance between the plates is relatively close (this is the pursuit of multiple laps) Avoided), distributed capacitance provides a path for high frequency signals.