Electronics > Projects, Designs, and Technical Stuff
CPLD erase from Airport X-ray scanners
EEEnthusiast:
Has anybody experienced a complete erasure of a CPLD logic when it passed through an airport X-ray machine? Or may be some other scanner used in the airport?
T3sl4co1l:
FYI, I've passed my laptop through, in standby, with no apparent change in operation when later opened. (That would be a target size of, less than 1GB I think, of active, in use, RAM. Data that I would expect might cause a crash if it gets corrupted.) I would expect DRAM to be more vulnerable to EEPROM cells, or some Flash. (I wouldn't think CPLDs are using the latest, highest density Flash processes, no?)
AFAIK, erasing EEPROMs is possible with x-rays, but only with extreme levels, levels that cause rapid and permanent damage to the chip. Whereas electronic erase cycles might be 10^5, or UV cycles might be 10^3, x-ray cycles are like... 10^1 if that. Or something.
Also AFAIK, most programmable devices are rated for assembly inspection x-raying, which are probably around the same level?? I can't remember actually reading such a rating actually, but it must exist? There are plenty of no-lead packaged devices out there, that would need to be x-rayed, that can be supplied pre-programmed. Which means they need to retain their programming through soldering cycles, too.
Tim
SiliconWizard:
--- Quote from: T3sl4co1l on February 02, 2020, 04:38:26 pm ---FYI, I've passed my laptop through, in standby, with no apparent change in operation when later opened. (That would be a target size of, less than 1GB I think, of active, in use, RAM. Data that I would expect might cause a crash if it gets corrupted.) I would expect DRAM to be more vulnerable to EEPROM cells, or some Flash. (I wouldn't think CPLDs are using the latest, highest density Flash processes, no?)
--- End quote ---
I've done that many times too and never experienced any issue. Even when left in standby.
--- Quote from: T3sl4co1l on February 02, 2020, 04:38:26 pm ---AFAIK, erasing EEPROMs is possible with x-rays, but only with extreme levels,(...)
Also AFAIK, most programmable devices are rated for assembly inspection x-raying, which are probably around the same level??
--- End quote ---
I'll say yes and yes.
And I'd say typical inspection x-ray machines have significantly higher level.
magic:
There is also a whole bunch of actual EEPROMs and Flash in computers and other consumer electronics which go through those scanners.
filssavi:
I fly fairly often, so I have USB keys, sata SSDs (MLC), laptops and tablets go through x ray scanners 5/10 times a year and I have never had any problems. I expect CPLDs to be much less susceptible as they are usually manufactured on very old nodes (the older the node, the larger the feature size, the higher the energy needed to flip a bit)
Also I think complete erasure is basically impossible, unless you exposed the memory to extreme levels of radiations (nuclear reactor type levels), I would expect more of an erratic behaviour due to single bit flips (I seriously doubt CPLDs do crac checks on startup)
Anyway airport scanners are allegedly designed to be film (as in photographic film under ISO800 sensitivity) safe, and I expect that to be quite more sensitive than flash
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