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We're looking for a flash device for a low-volume (batches size < 100) industrial product, in the 2/4/8 GByte range.

In applications like this we've previously used SD card, which is an obvious choice. For better mechanical robustness and device consistency, we'd really like to use a fixed IC in this product. It feels like eMMC is absolutely the obvious choice for this - avoid both the NAND management hassle and the downsides of SD-cards.

However, there is something about the supply of eMMC devices which makes me suspicious about whether they're a sensible choice. Supply from the usual catalogue companies (Mouser,DK and Farnell for us) is really patchy, with few parts listed, those that are listed not on manufacturers' websites and many with 1000-level MOQs. This is not just 'difficult' manufacturers (Samsung, etc), people like Micron who have DRAM parts widely available seem to be different for eMMC.

Obviously the Arrows & Avnets of the world list everything, but this doesn't mean I could actually have 50 parts tomorrow from them.

Is there something odd about eMMC (licensing, whatever) which I'm missing, which means that it's not being carried in the normal way? Are there people here with any experience of using eMMC in real, low-volume, production?

Glorfindel
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  • https://events.linuxfoundation.org/sites/events/files/slides/brezillon-nand-framework_0.pdf Here's something interesting to read that explains why designers favor emmc over raw nand recently. – user3528438 Apr 22 '17 at 05:16

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I think there is just not as much demand for emmc. We looked at it and decided it made more sense to just roll the controller into our chip. We were attracted by the integrated controller at first but that feature adds cost to raw NAND so it didn't make sense for us. I bet a lot of other people feel the same way.

I would think using sd cards for long term deployment would be risky especially now that they're using TLC flash in them. Talk to your ae about bit rot, they wouldn't give exact numbers last time we spoke but they weren't pretty less than a year if I remember right.

If you are concerned about supply in the future I'd encourage you to contact your micron rep. They have a separate list of memory and flash parts that they guarantee to carry for a long time, and if memory serves me a smaller list that they'll carry for even longer :)

Some Hardware Guy
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  • Sadly 'talk to your Micron rep' isn't as satisfactory process as it might be if you're only buying handful of parts. (I say this based on generic experience, not of Micron particularly). We'll look at raw NAND again though, thanks. –  Oct 09 '15 at 16:13
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    I would say if you call in they'd at least tell you what emmc parts were on the extended life list. – Some Hardware Guy Oct 09 '15 at 16:15