A resistor will cause a voltage drop, and that could make problems for the functionality. Ferrite bead will not make a DC voltage drop.
For higher frequencies (above 100MHz) the bead is more precise described (Z, X and R), while the impedance of a resistor is maybe not defined. #Amund Fra: Amund Westin [mailto:am...@westin-emission.no] Sendt: 5. februar 2016 09:38 Til: 'EMC-PSTC@LISTSERV.IEEE.ORG' <EMC-PSTC@LISTSERV.IEEE.ORG> Emne: Ferrite bead vs. resistor Had some EMI issues, caused by a LVDS line. By inserting CM chokes, the radiation seemed to lower significant. Inserting resistors as well (aprox 22 ohm) made it even better. I can’t check the eye curve, but 22ohm makes no problem with the EUT operation. But, should the series resistor be replaced by ferrite beads instead? Will it make any really differences? The LVDS clock is approx 40MHz and data rate 160Mbps. #Amund - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
