AC Line Filters – Common Mode SC Coils, SC-J Series, Terminal Base Type
Magnetic Permeability of Ferrite Material
Inꢀorderꢀtoꢀachieveꢀmostꢀefficientꢀnoiseꢀreduction,ꢀitꢀisꢀimportantꢀtoꢀselectꢀtheꢀmaterialꢀaccordingꢀtoꢀtheꢀtargetꢀfrequencyꢀ
band.ꢀDependingꢀonꢀitsꢀmagneticꢀpermeability,ꢀaꢀparticularꢀferriteꢀmaterialꢀwillꢀbeꢀeffectiveꢀinꢀaꢀcertainꢀfrequencyꢀband.
Aꢀschematicꢀrepresentationꢀofꢀtheꢀrelationshipꢀbetweenꢀtheꢀmagneticꢀpermeabilityꢀofꢀeachꢀmaterialꢀandꢀtheꢀcorrespondingꢀ
effectiveꢀbandꢀrangeꢀisꢀshownꢀinꢀFigureꢀ1.ꢀMaterialsꢀwithꢀhigherꢀmagneticꢀpermeabilityꢀareꢀeffectiveꢀinꢀtheꢀlowerꢀfrequencyꢀ
range,ꢀwhileꢀthoseꢀwithꢀlowerꢀmagneticꢀpermeabilityꢀareꢀeffectiveꢀinꢀtheꢀhigherꢀfrequencyꢀrange.ꢀThus,ꢀMn-Znꢀproductsꢀareꢀ
mainlyꢀusedꢀforꢀreducingꢀconductionꢀnoise,ꢀwhileꢀNi-Znꢀproductsꢀareꢀcommonlyꢀusedꢀforꢀradiationꢀnoiseꢀcountermeasures.
Theꢀeffectiveꢀfrequencyꢀrangeꢀvariesꢀdependingꢀonꢀcoreꢀshape,ꢀsizeꢀandꢀnumberꢀofꢀwindings.ꢀThisꢀfrequencyꢀdependenceꢀ
ofꢀtheꢀmagneticꢀpermeabilityꢀasꢀshownꢀinꢀtheꢀfigureꢀservesꢀforꢀreferenceꢀpurposesꢀonlyꢀandꢀitꢀshouldꢀbeꢀtestedꢀonꢀtheꢀactualꢀ
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
ꢅꢁ,ꢁꢁꢁ
ꢃiꢌꢐer maꢌnetiꢍ permeaꢎilityꢏ
ꢃiꢌꢐer noise sꢑppression eꢒꢒeꢍt
in tꢐe loꢋer ꢒreꢓꢑenꢍy ranꢌe
ꢋꢇꢑꢒꢇ ꢓerieꢔ
Sꢀꢉꢃ
Sꢀꢊꢃ
ꢀꢁꢃ
ꢀꢁ,ꢁꢁꢁ
Loꢋer maꢌnetiꢍ permeaꢎilityꢏ
ꢃiꢌꢐer noise sꢑppression eꢒꢒeꢍt
in tꢐe ꢐiꢌꢐer ꢒreꢓꢑenꢍy ranꢌe
ꢈꢃ
ꢊꢃ
ꢐiꢑꢒꢇ ꢓerieꢔ
ꢀꢇꢁꢁL
ꢈꢁꢁL
ꢁ
ꢀꢁ ꢂꢃꢄ
ꢀꢁꢁ ꢂꢃꢄ
ꢀ Mꢃꢄ
ꢀꢁ Mꢃꢄ
ꢀꢁꢁ Mꢃꢄ
ꢀ ꢆꢃꢄ
ꢀꢁꢁeꢂꢃive ꢄreꢅꢆeꢇꢂꢈ ꢉaꢇꢊe
© KEMET Electronics Corporation • KEMET Tower • One East Broward Boulevard
Fort Lauderdale, FL 33301 USA • 954-766-2800 • www.kemet.com
LF0006_SC-J • 10/14/2019
2