Datasheet
3© KEMET Electronics Corporation • KEMET Tower • One East Broward Boulevard E5011_ESD-R-NC23 • 9/12/2018
Fort Lauderdale, FL 33301 USA • 954-766-2800 • www.kemet.com
EMI Core – ESD-R-NC23 Toroidal Nanocrystal Cores for Round Cables for Low & High Frequency (with case)
Magnetic Permeability of Ferrite Material
Inordertoachievemostecientnoisereduction,itisimportanttoselectthematerialaccordingtothetargetfrequency
band. Depending on its magnetic permeability, a particular ferrite material or metal material will be effective in a certain
frequency band. A schematic representation of the relationship between the magnetic permeability of each material and the
corresponding effective band range is shown in Figure 4.
Ferrite materials with higher magnetic permeability are effective in the lower frequency range, while those with lower
magnetic permeability are effective in the higher frequency range. Thus, Mn-Zn products are mainly used for reducing
conduction noise, while Ni-Zn products are commonly used for radiation noise countermeasures. Metal materials on the
other hand are effective throughout the broadband frequency range, in low as well as high frequencies.
The effective frequency range varies depending on core shape, size and number of turns. This frequency dependence of the
magneticpermeabilityasshowninthegureservesforreferencepurposesonlyanditshouldbetestedontheactualdevice
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 4 - 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
Magnetic Permeability
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
Nanocrystalline Core
Higher magnetic permeability:
Higher noise suppression effect in the broadband frequency range