Embedded SD card chips - Page 1
Forum section: electronics / general

author: Digibin
author_rank: Regular Contributor
timestamp: February 27, 2016, 05:55:18 pm
content: Does anyone know of any embedded SD card memory chips available from major distributors? By embedded I mean a part that is soldered down rather than an actual SD card.They don't seem to be very popular, I can only find two companies making them:http://www.sandisk.com/Assets/Categories/OEM/SanDisk_iNAND_0108.pdfhttp://www.dacomwest.de/fileadmin/Dacom/Dokumente/Cactus%20Technologies/Serie_806/CT_PM_SD-806_1.6.pdfAnd neither of these are stocked by the major distributors.

author: Kilrah
author_rank: Unknown
timestamp: February 27, 2016, 06:02:20 pm
content: It's usually referred to as eMMC, you might have better results with that term.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: February 27, 2016, 06:22:04 pm
content: Search findchips for emmc0 or emmc1 to find a few Kingston parts in stock

author: Digibin
author_rank: Regular Contributor
timestamp: February 27, 2016, 06:51:32 pm
content: Nothing in stock in the UK unfortunately. I'm surprised at how unpopular these parts appear to be!

author: Yansi
author_rank: Super Contributor
timestamp: February 27, 2016, 08:02:07 pm
content: Probably not popular bcs od quad-spi flash memories, although less capacity.

author: Kilrah
author_rank: Unknown
timestamp: February 27, 2016, 08:23:08 pm
content: They are/were ubiquitous in things like cheap smartphones and tablets - but that's usually both designed and built very far away from here.The microSD card and captive socket solution is quite popular too for devices that can acommodate the larger physical size.

author: Artlav
author_rank: Frequent Contributor
timestamp: February 27, 2016, 11:20:07 pm
content: If you don't mind me asking, how is that better than a regular microSD card in a holding (captive) socket?

author: Stonent
author_rank: Super Contributor
timestamp: February 27, 2016, 11:44:11 pm
content: Legally? What are they going to do? I might just have them do pick and place with the uSD socket and pop the uSD card in it with a dot of super glue on it to keep it from coming out after you test it.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: February 28, 2016, 01:05:01 am
content: AIUI you need to be a member of the SD card cartel to get the specs for full-speed access, but I don't recall ever seeing any reference to patents though. The usual issue of using logos obviously isn't relevant here.I think the SD card people collect a royalty on cards manufactured ( good luck with enforcing that on Chinese manufacturers though).

author: Digibin
author_rank: Regular Contributor
timestamp: February 28, 2016, 11:40:09 am
content: Quote from: Artlav on February 27, 2016, 11:20:07 pmWell I could do that, but the PCB is fully exposed so I don't want to encourage people to try to remove it. If you see a regular microSD card you might try to remove it for whatever reason, or just by 'fiddling' with it, but if you see a soldered down part you just leave it alone. Even with a dab of glue underneath people would still try to take it out. In fact you would think, given it's all exposed, that a card + card holder was used precisely so it can be replaced, which is not the case.I can buy the SanDisk iNAND parts from arrow.com in the states but their cheapest shipping cost to the UK is nearly $40 (the part costs $6).And yes I'm using it in SPI mode.

author: XOIIO
author_rank: Super Contributor
timestamp: February 28, 2016, 12:09:41 pm
content: Maybe just reflow solder the SD card right to the board, and use some sort of shield to hide it?

author: Jeroen3
author_rank: Super Contributor
timestamp: February 28, 2016, 01:25:44 pm
content: What is wrong with a normal spi flash chip?

author: Artlav
author_rank: Frequent Contributor
timestamp: February 28, 2016, 01:46:17 pm
content: How about both - put a regular card into a socket, and then solder an "RF can" kind of shield above it to discourage people from trying to remove it?Quote from: Jeroen3 on February 28, 2016, 01:25:44 pmI would guess size.I was looking for a low-pin-count storage recently, and the largest SPI flash chips i've found were in the 64-128Mb range at $5-10 apiece, while 2Gb microSD cards go for about $1 at 10+ quantity.

author: Jeroen3
author_rank: Super Contributor
timestamp: February 28, 2016, 03:31:23 pm
content: Looking in DigiKey it seems you're right. There are no low pin count high memory serial devices.Either serial or an SD card. Is there no market for this?

author: Stonent
author_rank: Super Contributor
timestamp: February 29, 2016, 06:51:05 am
content: Quote from: XOIIO on February 28, 2016, 12:09:41 pmMaybe put a blob of black epoxy on top and hide it like any COB.Or...Dab some solder paste across the contacts in the uSD slot, insert the uSD card and give it a few seconds with the reflow gun.Or.....http://www.dotmana.com/weblog/2015/08/microsd-card-reflow-quick-and-dirty-pcb-with-kicad/Found on Reddit: