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  1. #1
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    Problem with continuity of PIN.57 and PIN.25 in PIC32MX

    Hi friends,
    Anyone can help me.
    If u have any PIC32MX controllers please check continuity of PIN.57(RED probe) and Pin.25(Black probe.). In my circuit it seems to be short(I think internally) and I can't program it. I tried even new PIC32 and checked it before soldering.
    (64 pin PIC32)

    So please help me by providing the result with ur controller



    Thanks...

  2. #2
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    Re: PIC32MX Problem

    hey,
    please its urgent!!!!!!!!!



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  3. #3
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    Re: PIC32MX Problem

    You don't say which Pic32 you are using.

    Pin 57 is Supply or voltage reg enable and Pin 25 is Ground.
    I have not had a problem with the M32 I have used.
    If these pins were internally shorted then the chip would draw large current from the power supply and get very hot.



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    Re: PIC32MX Problem

    Quote Originally Posted by btbass
    You don't say which Pic32 you are using.

    Pin 57 is Supply or voltage reg enable and Pin 25 is Ground.
    I have not had a problem with the M32 I have used.
    If these pins were internally shorted then the chip would draw large current from the power supply and get very hot.
    Thank u.
    I am using PIC32MX575F256H. I checked about 8 controllers (PIC32mx575f256h) the same problem.

    Sir could u please help me.
    Its urgent
    Thank u ir.



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    Re: PIC32MX Problem

    Then Pin 57 is supply and Pin 25 is Ground.
    Power up your board and measure the voltage across those Pins, it should be nominally 3.3 volts, no more than 3.6 volts max.

    I can not see any supply decoupling on your board?
    You need to have 100nF ceramic caps mounted close to the supply pins.

    Vdd on 10, 26, 38, 57.
    Vss on 9, 25, 41.
    AVdd on 19.
    AVss 0n 20.

    All these pins should be decoupled, without decoupling the micro could be unstable.


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  6. #6
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    Re: PIC32MX Problem

    Sir I am using another board for programming my PIC32.
    And after powering the device(3.3v) the voltage get reduced to 0.66v.


    Thank u sir.



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    Re: PIC32MX Problem

    The micro should only draw about ~50mA when you power it up for programming?
    Is the programmer supplying the power supply?

    You must have a short somewhere? It is unlikely that all your chips have the same fault.



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    Re: PIC32MX Problem

    Quote Originally Posted by btbass
    The micro should only draw about ~50mA when you power it up for programming?
    Is the programmer supplying the power supply?

    You must have a short somewhere? It is unlikely that all your chips have the same fault.
    But sir i checked the pin.57 and pin.25 even before soldering and the same problem.
    I tried both poering from external source and from PicKit3,but no use.

    I checked chips from different batch but the same problem(before soldering).

    Does all PIC32 chips have internal short.??



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  9. #9
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    Re: PIC32MX Problem

    I have three Pic32 chips mounted on Microchip PIM modules. They are in 100 Pin packages and they all work fine.

    If you are measuring a short between Pin 57 and Pin 25 on a chip before soldering it to the pcb, then the power supply is zapped.

    Pin 57 would also be short to Pins 9 and 41, the other ground pins.

    You must have a faulty batch of chips so you need to get in touch with Microchip support or your component supplier.



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  10. #10
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    Re: PIC32MX Problem

    Quote Originally Posted by btbass
    I have three Pic32 chips mounted on Microchip PIM modules. They are in 100 Pin packages and they all work fine.

    If you are measuring a short between Pin 57 and Pin 25 on a chip before soldering it to the pcb, then the power supply is zapped.

    Pin 57 would also be short to Pins 9 and 41, the other ground pins.

    You must have a faulty batch of chips so you need to get in touch with Microchip support or your component supplier.
    Pin57 is only short with pin.25 not with other VSS pins.!!!!

    I already informed them and they replaced my PIC32s with new but the same problem with new PIC32s I don't know why???



  11. #11
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    Re: PIC32MX Problem

    Have you got a capacitor connected from Pin 56, Vcap/Vddcore, to ground?
    Data sheet Section 2.3.

    This cap is needed for the core voltage regulator in the chip which is derived from Pin 57.



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    Re: PIC32MX Problem

    Quote Originally Posted by btbass
    Have you got a capacitor connected from Pin 56, Vcap/Vddcore, to ground?
    Data sheet Section 2.3.

    This cap is needed for the core voltage regulator in the chip which is derived from Pin 57.
    Ya two capacitors
    100nf and 10uf

    Thanks



  13. #13
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    Re: PIC32MX Problem

    Try disconnecting just that pin and see what happens?

    They have changed the pin function on the later devices, that used to be reg enable. Maybe the data sheet is wrong?

    Long shot but what have you got to loose?



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    Re: PIC32MX Problem

    Quote Originally Posted by btbass
    Try disconnecting just that pin and see what happens?

    They have changed the pin function on the later devices, that used to be reg enable. Maybe the data sheet is wrong?

    Long shot but what have you got to loose?
    I already tried it but no use.

    Thank for ur suggestions sir.
    Now I decided to use their old PIC32MX4xx/3xx devices in my project. This problem wasted my two-three weeks and money.
    Do u have any experience with their PIC32MX4xx/3xx devices.:D:D:D:D
    Because I don't like to waste my time and money .

    again thank u sir.



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    Re: PIC32MX Problem

    I have successfully used the 360F512L and the 795F512L.

    I am at present working with the usb and can modules in the 795.
    Both of these chips are in 100 pin packages.
    I do intend to migrate the code to a 575F256H in a 64 pin package for the final product. I hope I dont meet the same problems as you when I move to the smaller package.



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  16. #16
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    Re: PIC32MX Problem

    Quote Originally Posted by btbass
    I have successfully used the 360F512L and the 795F512L.

    I am at present working with the usb and can modules in the 795.
    Both of these chips are in 100 pin packages.
    I do intend to migrate the code to a 575F256H in a 64 pin package for the final product. I hope I dont meet the same problems as you when I move to the smaller package.
    Surely no sir.
    Its(My) an exceptional case ,...:D:D:D:D



  17. #17
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    Re: PIC32MX Problem

    Try to stick with the Pic32MX, it is a very nice and powerful processor.
    I also work with arm nxp lpc2378, ok, but the mips core in the pic blows it out the water, no contest.



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    PIC32MX Problem

    Sure...
    As my name PIC_FOR_ALL



  19. #19
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    Re: PIC32MX Problem

    Finally the problem solved...
    My friend Anand (anandpv2009 in this forum, he is my colleague) solved the problem. He corrected the board position. And now my controllers are works fine and perfect.


    Thanks btbass,



  20. #20
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    Re: PIC32MX Problem

    Haha..
    Ok good luck PICFORALL :D:D:D



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