Difference between revisions of "EMI suppression cores"
From Granite Devices Knowledge Wiki
| [checked revision] | [checked revision] |
| Line 4: | Line 4: | ||
==Selection== | ==Selection== | ||
For motor control applications it is recommended to get low to medium frequency ferrite beads for maximum efficiency. | For motor control applications it is recommended to get low to medium frequency ferrite beads for maximum efficiency. | ||
| − | ;Preferred | + | ;Preferred types |
*Core material designed for low to medium frequency bands (attenuation between 1-300 MHz) | *Core material designed for low to medium frequency bands (attenuation between 1-300 MHz) | ||
*Large enough to fit cable multiple rounds through it | *Large enough to fit cable multiple rounds through it | ||
| − | ;Avoid | + | ;Avoid these |
*Core material designed for high frequency bands (above 300 MHz) | *Core material designed for high frequency bands (above 300 MHz) | ||
*Inductor cores - will just add inductance and make things worse | *Inductor cores - will just add inductance and make things worse | ||
Revision as of 22:34, 18 April 2012
EMI suppression cores a.k.a. ferrite beads are an efficient way to reduce high frequency interference from wiring. Adding ferrute beads to signal & power wiring is recommended if signal reliability problems are encountered.
Selection
For motor control applications it is recommended to get low to medium frequency ferrite beads for maximum efficiency.
- Preferred types
- Core material designed for low to medium frequency bands (attenuation between 1-300 MHz)
- Large enough to fit cable multiple rounds through it
- Avoid these
- Core material designed for high frequency bands (above 300 MHz)
- Inductor cores - will just add inductance and make things worse
- Iron powder cores
Most ferrite & iron powder cores look same. So if unsure about material properties, its most safe bet to purchase low to medium frequency beads from distributors such as:
- Digikey
- Mouser
- Farnell
Some popular ferrite bead brands:
- Laird-Signal Integrity Products
- Fair-Rite
