Craig, no matter how you ultimately choose to address your issue, the 81 slide presentation linked here should be instructive: http://www.x2y.com/publications/cmcreplace.pdf Steve On 9/12/2014 2:11 PM, Craig Francis wrote: > SI-LIST, > Thanks for the insight. > > My application is like Randy described: low data rates (think 1Mbps) driven > by microprocessors and cables between PCBs within a chassis. > Some people put ferrites on single-ended signals before the connector to > reduce the high frequency content of the signal and prevent unnecessary > high-frequency radiation. > > Murata sells ferrite arrays for this purpose: > http://www.murata.com/en-us/products/emc/emifil/bl but I understand that > they are in the business of selling ferrite beads. > > I was wondering why I never see the ferrites applied to differential pairs, > only common-mode chokes. But it sounds like there are better matched > filters for differential pairs to reduce common mode conversion. > > However, there appears to be a large disagreement on using ferrites on > signal lines at all. Application notes and books offer contradictory > information and now I am more confused than I started. > > Thanks, > Craig Francis > > On Fri, Sep 12, 2014 at 2:04 PM, steve weir <weirsi@xxxxxxxxxx> wrote: > >> Some generalizations are more general than others. >> >> Steve >> On 9/12/2014 8:47 AM, Orin Laney wrote: >>> All generalizations are false. >>> >>> -----Original Message----- >>> From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] >> On >>> Behalf Of Lee >>> Sent: Friday, September 12, 2014 8:15 AM >>> To: clfranci@xxxxxxxxxxx; si-list@xxxxxxxxxxxxx >>> Subject: [SI-LIST] Re: Ferrite Beads on Differential Signal Lines? >>> >>> It makes no sense to put ferrite beads in any signal line. How did this >> get >>> started? >>> >>> -----Original Message----- >>> From: Craig Francis >>> Sent: Thursday, September 11, 2014 4:11 PM >>> To: si-list@xxxxxxxxxxxxx >>> Subject: [SI-LIST] Ferrite Beads on Differential Signal Lines? >>> >>> SI-List, >>> I haven't seen any literature concerning using ferrite beads on each >> signal >>> line of a differential pair. >>> Usually only a common-mode choke is used to reduce common-mode EMI. >>> >>> Can ferrite beads be used on a differential pair to increase the the rise >>> time of the signal and reduce unnecessary high-frequency content that may >>> radiate? >>> >>> The two ferrite beads would be sized to allow the bandwidth necessary for >>> the differential signal's highest data rate. >>> >>> >>> Thanks, >>> Craig Francis >>> >>> >>> ------------------------------------------------------------------ >>> To unsubscribe from si-list: >>> si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field >>> >>> or to administer your membership from a web page, go to: >>> //www.freelists.org/webpage/si-list >>> >>> For help: >>> si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field >>> >>> >>> List forum is accessible at: >>> http://tech.groups.yahoo.com/group/si-list >>> >>> List archives are viewable at: >>> //www.freelists.org/archives/si-list >>> >>> Old (prior to June 6, 2001) list archives are viewable at: >>> http://www.qsl.net/wb6tpu >>> >>> >>> >>> >>> ----- >>> No virus found in this message. >>> Checked by AVG - www.avg.com >>> Version: 2014.0.4765 / Virus Database: 4015/8184 - Release Date: 09/09/14 >>> >>> ------------------------------------------------------------------ >>> To unsubscribe from si-list: >>> si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field >>> >>> or to administer your membership from a web page, go to: >>> //www.freelists.org/webpage/si-list >>> >>> For help: >>> si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field >>> >>> >>> List forum is accessible at: >>> http://tech.groups.yahoo.com/group/si-list >>> >>> List archives are viewable at: >>> //www.freelists.org/archives/si-list >>> >>> Old (prior to June 6, 2001) list archives are viewable at: >>> http://www.qsl.net/wb6tpu >>> >>> >>> ------------------------------------------------------------------ >>> To unsubscribe from si-list: >>> si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field >>> >>> or to administer your membership from a web page, go to: >>> //www.freelists.org/webpage/si-list >>> >>> For help: >>> si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field >>> >>> >>> List forum is accessible at: >>> http://tech.groups.yahoo.com/group/si-list >>> >>> List archives are viewable at: >>> //www.freelists.org/archives/si-list >>> >>> Old (prior to June 6, 2001) list archives are viewable at: >>> http://www.qsl.net/wb6tpu >>> >>> >>> >> >> -- >> Steve Weir >> IPBLOX, LLC >> 1580 Grand Point Way >> MS 34689 >> Reno, NV 89523-9998 >> www.ipblox.com >> >> (775) 299-4236 Business >> (866) 675-4630 Toll-free >> (707) 780-1951 Fax >> >> All contents Copyright (c)2013 IPBLOX, LLC. All Rights Reserved. >> This e-mail may contain confidential material. >> If you are not the intended recipient, please destroy all records >> and notify the sender. >> >> ------------------------------------------------------------------ >> To unsubscribe from si-list: >> si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field >> >> or to administer your membership from a web page, go to: >> //www.freelists.org/webpage/si-list >> >> For help: >> si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field >> >> >> List forum is accessible at: >> http://tech.groups.yahoo.com/group/si-list >> >> List archives are viewable at: >> //www.freelists.org/archives/si-list >> >> Old (prior to June 6, 2001) list archives are viewable at: >> http://www.qsl.net/wb6tpu >> >> > > ------------------------------------------------------------------ > To unsubscribe from si-list: > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field > > or to administer your membership from a web page, go to: > //www.freelists.org/webpage/si-list > > For help: > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > > List forum is accessible at: > http://tech.groups.yahoo.com/group/si-list > > List archives are viewable at: > //www.freelists.org/archives/si-list > > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > > > -- Steve Weir IPBLOX, LLC 1580 Grand Point Way MS 34689 Reno, NV 89523-9998 www.ipblox.com (775) 299-4236 Business (866) 675-4630 Toll-free (707) 780-1951 Fax All contents Copyright (c)2013 IPBLOX, LLC. All Rights Reserved. This e-mail may contain confidential material. If you are not the intended recipient, please destroy all records and notify the sender. ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List forum is accessible at: http://tech.groups.yahoo.com/group/si-list List archives are viewable at: //www.freelists.org/archives/si-list Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu