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krypro
Newbie
Newbie
5,551 Views
Registered: ‎06-10-2013

[Virtex 5] ML505 damaged - switching regulators ?

Hello everyone!

 

my hardware: Virtex5, Board - ML505

Virtex5ML505 completely stopped working/responding after the situation below on the picture:

Virtex5Damaged.jpeg

(Ctrl Line I had unknowingly connected via pullup resistor.)


I needed a constant high state to CtrlLine, therefore it attached a simply to the GPIO J5 - VCC3V3.

Then I turned off the power supply Virtex5ML505 (but DAC board still worked - and 3V3 was on pullup resistor), then I turned on Virtex5ML505 and that was the end (Virtex5ML505 had died :/ ).

 

 

Here are some symptoms (when I turn on the power):

  • FPGA Virtex5 heats up quickly! (I immediately turn the power off to avoid burn Virtex5)
  • ERR red LED is lit and the green LED INIT
  • I can hear quiet hum from one of the DC switching regulators ;/ (I can not locate the exact)
  • JTAG does not work

I measure voltage on GIPO J5 after switching on board:
5V-> OK
3V3 -> ~ 2V.


Could it be damaged switching regulators 3V3 ? or maybe worse - Virtex5 damaged ?

Power Supply Diagram.PNG

 

I ask for advice on how to get to the correct diagnosis of my damage?

What should I next to do? 

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2 Replies
austin
Scholar
Scholar
5,549 Views
Registered: ‎02-27-2008

k,

 

From your diagram, I cannot see any reason why the board is failing, now.

 

Is it possible that you were not wearing a grounding strap, and you exposed the board (FPGA device) to a large ESD transient?

 

Is it possible that you connected something by accident, even for a instant, to a voltage higher than 3.3 volts?

 

It sounds like the device (the Xilinx FPGA is shorted on the 1.0 volt Vccint rail, which is consistent with electrical overstress (absolute maximum ratings in data sheet far exceeded), or ESD damage that completely wiped out junctions, gates, resulting in massive failure.

 

 

Austin Lesea
Principal Engineer
Xilinx San Jose
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krypro
Newbie
Newbie
5,533 Views
Registered: ‎06-10-2013



Is it possible that you connected something by accident, even for a instant, to a voltage higher than 3.3 volts?


Impossible


Is it possible that you were not wearing a grounding strap, and you exposed the board (FPGA device) to a large ESD transient?


 Jep, it's true, I was not wearing a grounding strap ;/

(before that, I could not believe that ESD can damage circuits..)

 

 

but, if possible, I will try to get the difference/damage/ by comparison to other ML505

 

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