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1996

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Subject:
From:
Dave Pavone <[log in to unmask]>
Date:
Fri, 05 Apr 96 06:17:18 EST
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     Mr Brooks
         The old rule of tumb was to set by-passes next to VCC so you did 
     not have a pwr trace running on top of your board the length of your 
     IC.
        How ever today most boards have planes for pwr, gnd So a even 
     matrics of bypasses across the board will do the trick.
     
     All you are doing is decoupling vcc,gnd, if done correctly the board 
     and parts will not make noise.
     
     
     
                           Hope this helps
                           DM PAVONE
                           Micros


______________________________ Reply Separator _________________________________
Subject: Placement of bypass caps
Author:  [log in to unmask] at SMTPLINK-Micros
Date:    4/4/96 5:45 PM


I have several sources (including the Motorola FACT book) that say bypass 
caps should be placed as close as possible to the GROUND pin of the IC (not 
the power pin.) But I have seen few really specific discussions of why this 
is so.
     
Some of my customers insist on having them placed as close as possible to 
the power pin.
     
Can anyone give me a definitive explanation of where they should be placed, 
and why?  Thanks
     
Doug Brooks
     



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