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scorpyann
Joined: 07 Nov 2006
Posts: 27
Location: Malaysia
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 07 May 2008 11:29 Trace Length Variation |
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"Trace length variation across DUTs should be kept within ±100ps."
Anybody know how much "±100ps" is in any measurement (inch(at)mils)?
Or anybody have formula on how to calculate it for certain material such as Nelco 13 or FR-4.
Pls help me!!
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abhi002
Joined: 08 Jun 2005
Posts: 161
Helped: 12
Location: india
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| 07 May 2008 16:28 Trace Length Variation |
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speed of signal at FR4 PCB is 140-180ps/inch
In ur case for +-100ps
length should be 0.55-0.72 inches
with the above rule u can calculate.For more information refer to Chapter1 of High Speed Digital Design by Johnson&Graham
Regards
Abhishek
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scorpyann
Joined: 07 Nov 2006
Posts: 27
Location: Malaysia
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| 08 May 2008 0:39 Re: Trace Length Variation |
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Hi Abishek,
Thanks for the info
Regards
Scorpyann
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