pcb 4 layer design

Discussion in 'The Projects Forum' started by vivek20055, Feb 3, 2013.

  1. vivek20055

    Thread Starter Member

    Nov 4, 2012
    88
    0
    Hi Kapil,

    My professor suggested 5mm wide trace in several layers for the input(24V)

    But my input contains 24V and 1.5 amperes current(not high current)

    So, what is the need of using 4 layers for the input(we can give in just one layer. Right?)

    But this input goes to inductor and then tank capacitors(LC circuit).

    Both ends of capacitors are connected mosfets. These Mosfets switching on/off alternatively with the help of controller.

    So due to magnetic flux high current will be produced into the coil for welding purpose.

    But, I dont understand,what is the need of using 4 layers for the input(we can give in just one layer. Right?)

    I am adding pictures of circuit and PCB

    Regards,
    Vivek Alaparthi
     
  2. MrChips

    Moderator

    Oct 2, 2009
    12,420
    3,355
    Four layers need to be considered when:

    1) there is a concern with high frequency operation
    2) you desire optimum low noise performance
    3) the layout is complex with potentially many cross-overs and vias

    When any one of the above conditions exists, it is common practice to dedicate one layer entirely to Vcc and another layer entirely to GND. This leaves two layers for signal routing.

    I consider anything above 1A to be high current. 2mm traces would work but 5mm would be better.
     
  3. kubeek

    AAC Fanatic!

    Sep 20, 2005
    4,670
    804
    I think you´re still missing the point of an LC tank circuit. The supply current through the two transistors might be just 1.5A, but the current exchanged between the L and C of the tank circuit can be orders of magnitude higher.
     
  4. vivek20055

    Thread Starter Member

    Nov 4, 2012
    88
    0
    Hi,

    How can I calculate trace width based on current at that point?

    Any site for trace width calculation?


    Regards,
    Vivek Alaparthi
     
  5. t06afre

    AAC Fanatic!

    May 11, 2009
    5,939
    1,222
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