problem with analog ground(AGND)

Discussion in 'The Projects Forum' started by vivek20055, Feb 11, 2013.

  1. vivek20055

    Thread Starter Member

    Nov 4, 2012
    88
    0
    Hi,

    I am designing a 4 layer pcb board. For the GND layer I have given seperate GND ground for high current path(from transistors) which is connected to normal GND at a point.

    I have given the seperate analog ground(AGND).

    My professor commented like this:

    If you only have analog parts over the analog GND then it is good that you are using a separate analog gnd but I am surprised that the analog part is so spread. A problem might be that your analog GND is connected at the end of the digital GND and digital noise will be added to your analog gnd. A start connection to the common GND separation might improve.


    what does this mean?????

    How can I add start connection???

    I am adding image with this message

    Regards
    Vivek Alaparthi
     
    • GND.png
      GND.png
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    Last edited: Feb 11, 2013
  2. Sensacell

    Well-Known Member

    Jun 19, 2012
    1,128
    266
    I believe your Professor means "Star Connection" - Google this.
     
  3. vivek20055

    Thread Starter Member

    Nov 4, 2012
    88
    0
    Hi,


    I need to use star point grounding connection for AGND and GND in PADS software??


    I have seperate copper areas for GND and AGND in my 4 layer pcb design.


    How can I implement star point grounding connection for AGND and GND???


    I am attaching the image for AGND and GND of my design???



    Regards
    Vivek
     
    • GND.png
      GND.png
      File size:
      35.1 KB
      Views:
      14
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