Use this electronics calculation for a first-pass component, converter, signal, motor, or sensor estimate when the stated operating conditions and units match the device data.

Inductance (H)

Filter inductance in henries.

Capacitance (F)

Filter capacitance in farads.

Compute the cutoff frequency in kilohertz of an LC EMI filter from its inductance and capacitance using SI units. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Cutoff frequency (kHz)

Corner frequency of the filter.

• EMI attenuation and protection calculations depend on source and load impedance, parasitics, layout, enclosure seams, cable coupling, frequency, pulse shape, and test standard. Component impedance curves alone do not demonstrate emissions, immunity, or ESD compliance.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check the result against the current datasheet and worst-case operating corners, then verify the circuit or measurement with simulation and bench testing where failure matters.

• Capacitor SRF

  Compute the self-resonant frequency of a capacitor from its equivalent series inductance and capacitance.

• Decap Resonance

  Compute the resonant frequency in megahertz of a decoupling capacitor from its mounted series inductance in nanohenries and capacitance in nanofarads.

• Inductor SRF

  Compute the self-resonant frequency of an inductor from its inductance and parasitic winding capacitance.