Self Resonant Frequency of Capacitor

[MobiNaz]

Hi All,

I know every inductor has an SRF , Self resonant frequency which should be greater than operating frequency. Is there SRF for a capacitor too?

For these capacitors I could not find any

Your Search Results | element14 Australia

Thanks in advance

 

[FvM]

To answer the question yourself, consider what's a reasonable equivalent circuit for a capacitor (particularly a MLCC). In contrast to an inductor, that forms a parallel resonant circuit with the windings and terminal capacitance, the capacitor's parasitic inductance forms a series resonant circuit. Because the MLCC layers are electrically parallel connected, it's inductance is almost equal to a conductor block of the same size. This means, that the inductance numbers are mainly determined by the case size rather than production details.

You can expect, that same value, same size capacitors from different vendors show an almost equal SRF. The actual resonance frequency observed in a circuit also depends on the overall geometry, e.g. the capacitor's height above a ground plane and the trace lengths. If the vendor's measurement setup to determine the SRF isn't exactly specified (e.g. the fixture geometry), the numbers are of limited use.

 

[Darkcrusher]

For a 100pf chip capacitor, self resonance is around 1GHz. This is no real problem. It only states that capacitance value will change with frequency. The capacitance value is constant (to 1%) if the self resonance is 10 times higher than your application frequency