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© KEMET Electronics Corporation • KEMET Tower • One East Broward Boulevard

LF0022_SS11VL • 6/14/2019

Fort Lauderdale, FL 33301 USA • 954-766-2800 • www.kemet.com

AC Line Filters – Common Mode SS Coils, 11VL Series

Magnetic Permeability of Ferrite Material

Inordertoachievemostefficientnoisereduction,itisimportanttoselectthematerialaccordingtothetargetfrequency

band.Dependingonitsmagneticpermeability,aparticularferritematerialwillbeeffectiveinacertainfrequencyband.

Aschematicrepresentationoftherelationshipbetweenthemagneticpermeabilityofeachmaterialandthecorresponding

effectivebandrangeisshowninFigure1.Materialswithhighermagneticpermeabilityareeffectiveinthelowerfrequency

range,whilethosewithlowermagneticpermeabilityareeffectiveinthehigherfrequencyrange.Thus,Mn-Znproductsare

mainlyusedforreducingconductionnoise,whileNi-Znproductsarecommonlyusedforradiationnoisecountermeasures.

Theeffectivefrequencyrangevariesdependingoncoreshape,sizeandnumberofwindings.Thisfrequencydependence

ofthemagneticpermeabilityasshowninthefigureservesforreferencepurposesonlyanditshouldbetestedontheactual

device to determine its effectiveness.

S18H, S15H, 10H, 7H, 5H, 1400L and 700L are KEMET’s proprietary ferrite material names. Other materials can also be

available on request.

Figure 1 - Relationship between the magnetic permeability of each material and its effective frequency range

10 kHz

0

10,000

20,000

100 kHz

1 MHz

10 MHz

100 MHz

1 GHz

Effective Frequency Range

Ni-Zn Series

1400L

700L

S18H

S15H

10H

7H

5H

Mn-Zn Series

Lower magnetic permeability:

Higher noise suppression effect

in the higher frequency range

Higher magnetic permeability:

Higher noise suppression effect

in the lower frequency range