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Jon Ledbetter
03/20/06 09:25
Read: 513 times


 
#112606 - Ground fill under crystal
The below questions assume a two layer PCB.

In the FAQ's http://www.8052.com/faq.phtml?FAQ=94

3. Ground-fill under the crystal might improve emissions. If you do ground-fill, it needs to be properly anchored.

From this post http://www.8052.com/forum/read.phtml?id=74689 , Kai shows what I believe is the bottom layer (or ground plane layer).



My question here is, should there be a copper fill under the crystal on the top layer as well tied to ground?

Also from the same FAQ.
2. Do not encircle the crystal with signals. It'll couple noise to whatever you connect. Run them on the same side of the crystal. And put a shield trace between the crystal signals and those I/O. If they go any distance, consider an R/C filter (47R and 0.001 uF depending on their speed).

In this, is the shield trace on both sides of the board and should it be tied to ground at the MCU on the top plane only?

Thanks
Jon

List of 6 messages in thread
TopicAuthorDate
Ground fill under crystal      Jon Ledbetter      03/20/06 09:25      
   Never Mind      Jon Ledbetter      03/20/06 15:23      
   Grounding at oscillator section      Kai Klaas      03/20/06 17:55      
      Thanks Kai      Jon Ledbetter      03/21/06 07:37      
         Aura?      Kai Klaas      03/21/06 08:13      
   RE: Aura      Jon Ledbetter      03/21/06 09:46      

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