Topic: FMC110 erratic behavior  (Read 7608 times)

pnumer November 18, 2014, 08:53 PM

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We have purchased ~20 FMC110 boards over the last 2 years.  They are mated to an ML605 in a small sensor.  Most of the boards work quite well, but some, especially those purchased more recently exhibit erratic behavior - they will frequently put out many very high signals, sometimes full scale, spaced randomly but in the 5-10 usec range.  Sometimes a power cycle will stop the behavior but sometimes it won't.  Each power cycle re-configures the board exactly as your reference design and goes through the calibration sequence to find the correct delay for each bit.  Frequently, a check of the calibration results shows 1 of the channels failing, almost always channel 1 which is the channel with the erratic behavior.  Do you have any thought or suggestions which might help us with this issue?  I am attaching a plot of the output of one of the boards with erratic output.

arnaudNL November 20, 2014, 05:19 AM (#1)

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Dear Sir,


Would you be able to provide me with a SN list of the board not working, I would like to personally check their test reports and report back to you. I would also like to check if there is anything special I can find about these boards.


Thanks,
Arnaud

pnumer November 20, 2014, 02:34 PM (#2)

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Arnaud -
The most troublesome board is sn: 1835.  Most of the time it comes up acting erratically after a power cycle.  Every so often though, it comes up stable.  We have noticed that those times it comes up stable the calibration bit delay values are all ~24-26 on ADC0.  When it comes up acting erratically the bit delay values range from 0 to 30. Also, it is always ADC0 that is the problem, ADC1 is always stable.

arnaudNL November 20, 2014, 05:10 PM (#3)

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Dear Sir,


Thanks for the info. I know it might sounds dumb but have you tried to clean the FMC connector with some alcohol and a toothbrush? We have seen strange issue on dirty FMC connectors. I notified our quality manager he will look at the situation.


Best Regards and thank you for the patience!


Arnaud

arnaudNL November 24, 2014, 05:49 AM (#4)

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Dear Sir,


Please keep me updated!


Thanks,
Arnaud

arnaudNL November 27, 2014, 06:57 AM (#5)

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Dear Sir,


I am forced to lock the topic in 24 hours without news from your side!


Thanks,
Arnaud

arnaudNL December 02, 2014, 06:20 AM (#6)

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This topic is being closed because the issue is considered as resolved by 4DSP. Feel free to create a new topic for any further inquiries.