Binchuan, a good common mode choke has: a high common mode impedance, and= =20 a low differential impedance. It doesn't eliminate common-mode noise, but= =20 it does attenuate it, without imposing much loss on the desired=20 differential signal. Regards, Steve. At 08:57 AM 10/9/2003 +0000, =AA=FC=A5=C8 wrote: > Dear all, > > I have one question from Ethernet design of Transformer which was > said could eliminate Common-mode noise. But I saw its equivalent > circuit designed just like two Inductance, so I have no idea about > why Transformer can eliminate Common-Mode noise? > > Could someone help me to clarify this question ? > > Sincerely your, > > Binchuan.Wang > > >------------------------------------------------------------------ >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 archives are viewable at: > //www.freelists.org/archives/si-list >or at our remote archives: > http://groups.yahoo.com/group/si-list/messages >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 archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu