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???
07/17/04 11:10
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Msg Score: +1
 +1 Informative
#74381 - RE: How good is this Board.
Responding to: ???'s previous message
Hallo Prahlad,

your layout looks nice!

Nevertheless, I would make some little changes:

1. Power supply plane and ground plane are interrupted at each chip pin row. This results in a loss of solidity of these planes.Try to make these planes run through all the pads, like it's shown here:




Don't worry about traces of only 13mil width. This is a standard dimension. It will help you to make the supply planes even run between the individual traces and by this heavily enhancing benefit of supply planes!

2. Do not connect the ground pins of 33pF capacitors to ground plane. They got their ground connection already on top layer. This will reduce ground noise a bit.

3. Power supply plane is relevantly interrupted arround connector X1. If you introduce some bridges for the lines running to this connector, then power supply plane is less broken.

4. I would insert a soft ferrite bead like BL02RN2 (Murata) or similar where the +5V enters the board, just between power supply connector and the 470µF power supply decoupling capacitor. This will heavily minimize high frequency currents running in the power supply cable!

Another point:
A cable leaves the board arround IC3 and IC4. As you do not provide any common mode filtering, this will result in heavy radiation. The same is valid for the other cables leaving your board.
I would bend each cable arround an individual soft ferrite ring core or feed it through a bigger soft ferrite bead. This will minimize common mode noise on each cable and by this minimize radiation.
In any case, keep the cables as short as ever possible!!

It can be helpful to insert 10...47Ohm resistors at outputs of 74HC541.

Good luck,
Kai

List of 22 messages in thread
TopicAuthorDate
How good is this Board.            01/01/70 00:00      
   RE: How good is this Board.            01/01/70 00:00      
      RE: How good is this Board.            01/01/70 00:00      
   RE: How good is this Board.            01/01/70 00:00      
      RE: How good is this Board.            01/01/70 00:00      
         RE: How good is this Board.            01/01/70 00:00      
            RE: How good is this Board.            01/01/70 00:00      
            RE: How good is this Board.            01/01/70 00:00      
         RE: How good is this Board.            01/01/70 00:00      
            RE: How good is this Board.            01/01/70 00:00      
      RE: How good is this Board.            01/01/70 00:00      
         Becomes better and better!            01/01/70 00:00      
            RE: Becomes better and better!            01/01/70 00:00      
               RE: Becomes better and better!            01/01/70 00:00      
   RE: How good is this Board.            01/01/70 00:00      
      RE: How good is this Board.            01/01/70 00:00      
         RE: How good is this Board.            01/01/70 00:00      
      RE: How good is this Board.            01/01/70 00:00      
   RE: How good is this Board.            01/01/70 00:00      
      To Purohit.            01/01/70 00:00      
         RE: To Purohit.            01/01/70 00:00      
   RE: How good is this Board.            01/01/70 00:00      

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