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.

Filter Resistance (Ω) (Ω)

Required number input.

Filter Reactance (Ω) (Ω)

Required number input.

Load Resistance (Ω) (Ω)

Required number input.

Estimate common-mode series-filter insertion loss into a resistive load from measured complex common-mode impedance at the selected frequency; source impedance is assumed zero. 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]

Attenuation (dB) (dB)

The resulting attenuation (db) returned as a number.

• 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.

• Differential Mode Filter Attenuation

  Estimate differential-mode series-filter insertion loss into a resistive load from measured complex differential-mode impedance at the selected frequency; source impedance is assumed zero.

• Ferrite Bead Insertion Loss

  Estimate small-signal insertion loss for a ferrite bead in series with a resistive load from the bead's resistive and reactive impedance at the selected frequency. The source is assumed ideal; use datasheet impedance at frequency and account for DC-bias effects separately.

• Common-Mode Choke Impedance

  Estimate one winding's series RL impedance magnitude at frequency f as √[R²+(2πfL)²]. Enter the effective common-mode inductance and resistance at the operating point; real choke impedance also includes core loss, capacitance, and self-resonance.