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I designed in an Everspin MRAM when they were a New Thing. That was a mistake. Rapidly designed it out. Our device used a magnet to activate a Hall Magnetic S
by rpaddock 4y ago
I designed in an Everspin MRAM when they were a New Thing.
That was a mistake. Rapidly designed it out.
Our device used a magnet to activate a Hall Magnetic Switch.
This magnet was about as strong as your typical Refrigerator Magnet.
I found that when it got close the the MRAM, which was possible in normal operation of the device, the MRAM was destroyed. To be clear it did not just change some bits. It became dead.
I sent these to Everspin and the report I got back was "The base plate was depolarized".
They did update some guidance to avoid magnetic fields after that.
At some point I saw a report that said they were having financial issues (Gee I wonder why, if your devices get erased by refrigerator magnets?). Today no browser will bring up their site:
"You can't visit www.everspin.com right now because its certificate has been revoked."
I've been told that Cyprus Semi, now part of Infineon, devices don't have this issue. I've not yet been willing to try them.
Something else most of this glowing reports, like the parent article, fail to report is that these devices take a lot of current during operation. So if you want to use them in a portable device, like ours, you have to be able to remove their power source and isolate their data pins.
- joezydeco 4y agoI'm using an FM25V10 (Cypress) part in a design and haven't seen a problem yet, but we're just hitting it with DC voltages during susceptibility testing. Now I'm curious to see what happens if we get it near an MRI unit.
- 55873445216111 4y agoCypress Semi (now Infineon) FRAM is ferro-electric. FRAM is not affected by magnetic fields at all. MRAM is ferro-magnetic and is affected by magnetic fields.
- pabs3 4y agoHmm, the Everspin site works for me now.