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???
01/01/06 16:40
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#106346 - Not a good idea for fast digital circuit
Responding to: ???'s previous message
Vignesh said:
Does this cause any other side effect, concerned to signal integrity?

Yes, unfortunately the connection between ground on die and ground plane becomes longer and longer. This results in increased inductance and ground bounce, which is highly disadvantageous.

Take care, microcontrollers are becoming faster and faster and the old DIL-40 package is no longer capable to provide ground connections of sufficient low inductance. Some members reported for instance, that AT89S52 seems to be more susceptible against noise compared to older AT89C52. Think about this.
For the same reason sockets can no longer be suggested for these big DIL-40 micros. The trend definitely goes towards TQFP-packages.

What you intend to do is, to use DIL-40 package plus socket plus this separate via construction for the ground pin. This results in much too high inductance and ground bounce! I would not do this.

Kai

List of 51 messages in thread
TopicAuthorDate
Second layer of PCBs            01/01/70 00:00      
   hmmm            01/01/70 00:00      
      Another idea...            01/01/70 00:00      
         A very good idea!            01/01/70 00:00      
         A clarification            01/01/70 00:00      
            This way?            01/01/70 00:00      
            No problem            01/01/70 00:00      
               better...            01/01/70 00:00      
                  That's the solution            01/01/70 00:00      
   Farady Cage ?            01/01/70 00:00      
      Oops!            01/01/70 00:00      
         Single double-sided PCB !            01/01/70 00:00      
            Depends            01/01/70 00:00      
               Layer            01/01/70 00:00      
      wow 12 replys in 1 hour !//            01/01/70 00:00      
         Yeah!            01/01/70 00:00      
   Close and solid ground plane            01/01/70 00:00      
      Thank you!            01/01/70 00:00      
   Some pics            01/01/70 00:00      
      Your Supply tracks are too thin            01/01/70 00:00      
         Thickness            01/01/70 00:00      
      Decoupling caps?            01/01/70 00:00      
      Top or botttom            01/01/70 00:00      
         Draw it            01/01/70 00:00      
            Ink != Etch resist            01/01/70 00:00      
               Indeed            01/01/70 00:00      
                  Time consuming            01/01/70 00:00      
                     Special ink            01/01/70 00:00      
               I would...            01/01/70 00:00      
                  is it for?            01/01/70 00:00      
                     Is because...            01/01/70 00:00      
                        Cant get anything better!            01/01/70 00:00      
                           It's easy to find all my posts...            01/01/70 00:00      
         DIP => Bottom Routing, Top Plane            01/01/70 00:00      
            Great!            01/01/70 00:00      
               Drilling is easier            01/01/70 00:00      
                  Another doubt            01/01/70 00:00      
                     Remedies            01/01/70 00:00      
                        My idea            01/01/70 00:00      
                           Not a good idea for fast digital circuit            01/01/70 00:00      
                              Try SMD            01/01/70 00:00      
                                 A new lowcost direct PCB printer ?            01/01/70 00:00      
                              SMD            01/01/70 00:00      
                                 The key to success is flux            01/01/70 00:00      
                                    Interesting link            01/01/70 00:00      
                                       Kai, you are right            01/01/70 00:00      
                                          Highly interesting article!            01/01/70 00:00      
                     Soldering            01/01/70 00:00      
   For your views..            01/01/70 00:00      
      Without schematic...            01/01/70 00:00      
         Schematic            01/01/70 00:00      

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