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Altera_Forum's avatar
Altera_Forum
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13 years ago

Internal Short Circuit Problem

Hello,

I'm a trainee from TIS circuit (Tunisia).I have a End of study project,it's about the off service circuit specially the EPM570T144C5N.

We use this QFP in our PCBs But we had faced a short circuit problem and after testingwe concluded that the EPM570T144C5N is the cause of the problem (internal short circuit).

I hope that You can help me resolve this problem and thank you.

3 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    13 years ago

    Hi, I don't know EPM570T144C5N, but I think it has a programmable interface (JTAG...)

    Where exactly do you have internal short-circuit ?

    On an user I/O pin, or on an other pin ?

    Between two pins near each other ?

    A soldering problem ?

    ...
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    13 years ago

    --- Quote Start ---

    Hi, I don't know EPM570T144C5N, but I think it has a programmable interface (JTAG...)

    Where exactly do you have internal short-circuit ?

    On an user I/O pin, or on an other pin ?

    Between two pins near each other ?

    A soldering problem ?

    ...

    --- Quote End ---

    No, we don't have soldering problem.

    short circuit between pin 3.3 V and ground (GND).

    We measured a value equivalent to Zerro Ohm between the branches (GND and 3.3V) using the multimeter and after removal of EPM570T144C5N.
  • Altera_Forum's avatar
    Altera_Forum
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    13 years ago

    If you have another blank PCB board, i recommed you to press the same CPLD on to it (dosen't need solder), then measure the resistance of VCC and Ground to eliminate the soldring problem.

    I think you may have a mistake during schmetic or PCB design, for example, the wrong pin define, or the pin index error of the package define.

    If you measure the resistance of the board after power up through a handheld multimeter, it may destroy the diveces!!!!