Giancarlo,I searched for Proximity effect & found similar question = answered by Dr. Howard Johnson.=20 The link is http://www.sigcon.com/Pubs%5Cnews%5C4_1.htm Hope it's useful = for=20 everyone. Thanx to everyone for participating in discussion. -----Original Message----- From: giancarlo guida [mailto:gguida@xxxxxxxxxx] Sent: Monday, July 19, 2004 4:17 PM To: Budathoki, Trilok (GE Consumer & Industrial) Subject: Re: [SI-LIST] Return path As general rule the return path current, in high frequency, will follow the path with minimum inductance Taking in to account the so-called proximity effect ( the return current will try to stay close to direct path) you can easily understand where the current should be. In practice you also must consider that the planes could not be so clean and resonance between plane could allow signal to be coupled out of your control Hope this help Giancarlo ----- Original Message ----- From: "Budathoki, Trilok (GE Consumer & Industrial)" <trilok.budathoki@xxxxxx> To: <si-list@xxxxxxxxxxxxx> Sent: Monday, July 19, 2004 12:40 PM Subject: [SI-LIST] Return path Hi I have a question.If we have stacking sequence given below.Return path = can be VCC plane (provided it's not broken) or Gnd plane. TOP GND1 LAYER3 LAYER4 VCC LAYER6 GND2 BOT If Layer 3 takes GND1 as return path, What will be return path for Layer = 4 & Layer 6. Why? Can anyone explain the theory / mechanism. Thanks Trilok Budathoki GE - India Business Center, *: 91-40-27881731 * : trilok.budathoki@xxxxxx ------------------------------------------------------------------ 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 FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org 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 FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org 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