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Conducted Emissions Converter

Convert conducted emission units between dBµV, dBµA, dBm, and dBmA at a LISN impedance.

Use this when: You need to correlate voltage and current measurements on power lines during CISPR conducted emissions testing.

Reference only. Verify against your calibrated setup, antenna calibration data, and the applicable standard before making compliance decisions.

Key formula

dBµA = dBµV − 20 × log₁₀(Z) · dBm = dBµV − (10·log₁₀(Z) + 90)

Example: 107 dBµV at 50 Ω → 0 dBm, 73 dBµA (34 dB below dBµV at 50 Ω LISN)

Related: dBm ↔ dBµV converter

dBµV
dBµA
dBm
dBmA
Ω

Offset: dBµV = dBm + 107 at this impedance

Why conducted emissions need their own converter

On a power line, the same disturbance can be written as a voltage across the LISN (dBµV), a current through a probe (dBµA), or a power into a known impedance (dBm). Conducted-emissions standards pick one of those on purpose. This converter keeps the impedance explicit so you can correlate a current-probe debug session with a LISN voltage limit.

Engineers reach for it when a pre-compliance current probe said “fine” and the accredited LISN said “fail,” or when a customer sent dBmA numbers from a factory scan and your limit table is in dBµV.

What to watch

The math assumes a defined impedance. A real LISN is 50 Ω in the RF path over a stated frequency range; it is not 50 Ω at 50 Hz. Do not use this tool to invent a pass if the probe was on a different conductor than the standard’s LISN port.

Frequently asked questions

Quick answers about using this calculator

When should I convert dBµV to dBµA?
When you measured current with a probe and need to compare it to a voltage limit, or the other way around. You still need the impedance that applies to that setup.
Is LISN impedance always 50 Ω?
The RF measurement port is typically 50 Ω over the CISPR conducted range. That is not the mains impedance at line frequency. Use the value from the method you are actually running.

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