Datasheet

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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)
Turns and Impedance Characteristics
When the desired performance of an EMI core cannot be
obtained with a single pass through the core, the impedance
characteristics can be changed with multiple turns.
A turn is counted by the number of lead-wire windings which pass
through the inner hole of the core. Windings on the outside of the
core do not count.
See Figure 1 for examples of one, two, and three turns.
Adding turns will result in higher impedance while also lowering
the effective frequency range.
See Figure 2 for an example.
Core Material and Effective Frequency Range
The Nanocrystal core material is typically
effective for frequencies in the broadband range.
See Figure 3.
It is recommended to measure the actual
frequency range effectiveness in the target
application.
3T2T1T
Figure 1 – How to count turns
Impedance Increase
Resonance point changes to lower band
3T
2T
1T
Impedance (Ω)
Frequency (MHz)
10,000
1 10 100 1,000
1,000
100
10
1
Figure 2 – Relationship between impedance and turn count.
(Representative example: ESD-R-16C)
Impedance (Ω)
Frequency (MHz)
AM band range FM band range
Mn-Zn series core
Ni-Zn series core
1,000
100
10
1
0.01 0.1 1 10 100 1,000
Nanocrystal series core
Figure 3 - Effective band range of Nanocrystal core material.
(Representative example, measured with same-dimension ring core)