Common Mode Choke

Butler Winding designs and manufactures common mode chokes for various noise cancellation and filtering applications. We will work with your engineers and plans to produce a Common Mode Choke that meets all your needs.


Where are Common Mode Choke Filters found?

  • Excessive line noise is present
  • In environments with high concentration of radio frequency waves

Dimensions of our Common Mode Chokes include:

  • Various standard types of “Core with Bobbin” structures (E, EP, EFD, PQ, POT, U and others)
  • Toroids
  • And some custom designs.

Common Mode Chokes are used when many electrical devices may be connected to the same power lines (or power supply lines) and therefore substantial electrical noise can exist on these lines.

Design upper limits of a common mode choke:

  • It is typical for the inductance value of a common mode choke to be specified as a minimum requirement, thus insuring the crossover frequency is not shifted too high.
  • The frequency range of the interfering signal should be given to allow proper calculation of the attenuation of unwanted signal noise in the design.
  • Proper wire sizing is accomplished by specifying the voltage and current levels across and passing through the common mode choke.

Common mode choke filter, line inductor, and differential choke designs vary widely in terms of power rating, inductance, voltage level (low to high), operating frequency, size, impedance, bandwidth (frequency response), packaging, winding capacitance, and other parameters.

If you need assistance with your design, please contact Butler Winding and ask for Engineering.