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Article #379Re: Dr Howard Johnson, this weeks guest on The Amp Hour
From: Tim Williams
Date: Wed, 11 Jan 2012 03:10
Date: Wed, 11 Jan 2012 03:10
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2895 bytes
"John Larkin" <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in message news:a6qog71oeiacboqnku38gr0qq7tnf4njfc@4ax.com... > He says that a transmission-line pcb trace must always be "referenced" > to the same "return current" plane it started with and shouldn't pass > through vias to become referenced to a different plane, or else the > return currents will get confused or go on strike or something. If > that were true, 98% or the multilayer boards on Earth would quit > working. > > He also says that you should add bypass caps and stitching vias to > conduct these return currents whenever a trace does via to a different > "reference plane." > > All silly. You're just spoiled... 8-layer boards aren't cheap. Heck, four layer boards aren't cheap. If I can avoid it, I'll pick 2 layer whenever possible. Great proto prices and turn arounds. With two layers to choose from, you have no choice but to stitch like a carpet. You only have room for one ground plane as such. Heck, if you think you have room for two (maybe VCC and GND), you're being lazy and could get by with 1 layer. :) Tim -- Deep Friar: a very philosophical monk. Website: http://webpages.charter.net/dawill/tmoranwms
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From: "Tim Williams" <tmoranwms@charter.net>
Newsgroups: sci.electronics.design,aus.electronics
Subject: Re: Dr Howard Johnson, this weeks guest on The Amp Hour
Date: Tue, 10 Jan 2012 21:10:15 -0600
Organization: A noiseless patient Spider
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