Inductive Components – ABC of Parameters: Inductance Dependency on Frequency

An inductor is not an ideal element; it contains certain parasitic resistance and capacitance values.

The operation of the inductor is greatly influenced by the aforementioned parasitic capacitance since it, along with the inductance of the element, forms a resonant circuit. The inductance of the coil increases until it reaches its peak value as the frequency approaches the resonant frequency. At the peak point, it then decreases to zero. When designing a device with coils, it is important to select them to operate with signals lower than the resonant frequency. It is worthwhile to check the documentation for the specific component to verify the frequency at which its inductance measurements were taken.