Collections

CISPR 22: EN 55022 EMC Standard

CISPR 22: EN 55022 EMC Standard

CISPR 22 is a widely used standard for electromagnetic compatibility within Europe for Information Technology Equipment, ITE. CISPR 22 is maintained by CISPR: the International Special Committee on Radio Interference

There is also another related standard: EN 55022 which is the CENELEC standard. EN 55022 is a modified derivative for CISPR 22 and as a result both standards are used within the industry.,

CENELEC is the European Committee for Electrotechnical Standardisation and has produced EN 55022 based upon the original CISPR 22 standard.

What is CISPR 22

CISPR 22 is the CISPR standard for Information Technology Equipment-Radio Disturbance Characteristics-Limits and Methods of Measurement.

CISPR 22 has been adopted for use by most members of the European Community.

CISPR 22 & FCC

With CISPR 22 being widely used within the European Community, it is often necessary to relate it to other standards, the main one being the FCC, Federal Communications Commission in the USA. Here the FCC Part 15 standard is used.

To ensure that either standard can be used to certify digital electronic equipment, FCC Part 15 and CISPR 22 have been made to be relatively harmonious, although there are a few differences.

CISPR 22 differentiates between Class A and Class B equipment and it gives figures for conducted and radiated emissions for each class. In addition, CISPR 22 requires certification over the frequency range of 0.15 MHz to 30 MHz for conducted emissions. On these points there are differences between CISPR 22 and the FCC Part 15.

Also CISPR 22 has no specified limits for frequencies above 1.0 GHz, and CISPR limits are provided in dBµV, while the FCC limits are specified in µV which means that a simple conversion is required for direct comparisons.

In terms of similarities the conducted and radiated emission limits specified in CISPR 22 and FCC Part 15 are close to each other, i.e. within a few dB of each other over the detailed frequencies.

In this way it is possible to meet both standards easily for the certification process.

Summary of CISPR 22 limits

The tables below give a summary of the field strength limits for conducted and radiated emissions within the per CISPR 22 standard.


CISPR 22 Class A Conducted EMI Limit
Frequency of Emission (MHz)Conducted Limit (dBµV)
Quasi-peakAverage
0.15 - 0.507966
0.50 - 30.07360

CISPR 22 Class B Conducted EMI Limit
Frequency of Emission (MHz)Conducted Limit (dBµ;V)
Quasi-peakAverage
0.15 - 0.5066 to 5656 to 46
0.50 - 5.005646
5.00 - 30.06050

CISPR 22 Class A 10-Metre Radiated EMI Limit
Frequency of Emission (MHz)Field Strength Limit (dBµV/m)
30 - 8839
88 - 21643.5
216 - 96046.5
above 96049.5

CISPR 22 Class B 3-Metre Radiated EMI Limit
Frequency of Emission (MHz)Field Strength Limit (dBµV/m)
30 - 8840
88 - 21643.5
216 - 96046.0
above 96054.0


Watch the video: Radiated and Conducted Emissions Testing - The ABCs of EMC E02 (September 2021).