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October 4, 2010 2:34 PM

Obscure USB Device Filter: help me identify a source for this USB type device.

I do know that this OEM USB type device was originally sourced from China via a distributor. Beyond that, we do not know the specifications or other information for us to procure this off-the-shelf component.

The microchip reads: 24C16AN.

Thank you!

posted by strangelove to Technology (5 answers total)

The AT24C16AN is an EEPROM, meaning it has some sort of custom data burned onto it. Is there another chip on the back side? There should be, as the AT24C16AN doesn't speak USB.
posted by zsazsa at 2:40 PM on October 4, 2010

Response by poster: Hi Zsazsa, you are correct; there is custom data on the chip. There is no other chip on the reverse, and I've updated photos on Flickr.
I am looking to procure the whole assembly.
Thank you, again.
posted by strangelove at 2:49 PM on October 4, 2010

Any clues as to what it's used for -- or in what kind of equipment it's used? Can you give any size reference?

I don't think it's USB; I think it's an I2C EEPROM on a daughtercard that will plug into some kind of generic edge connector on some kind of custom equipment.
posted by We had a deal, Kyle at 4:30 PM on October 4, 2010

Agreed, it's not a USB device as such. Some "personality plugs" for various devices and controllers have started to use the USB plug form factor because it's a cheap board-only design (i.e. can be used without a shell on the plug; only the socket end requires a proper connector), and look like this. If I were to guess, I'd say it's used as a security token or configuration device. That said, it's not terribly secure as the 24C16 is a straightforward I²C device with no in-built security, and can easily be read by bit-banging a standard serial or parallel interface.

"…we do not know the specifications or other information for us to procure this off-the-shelf component."

It's not really an off-the-shelf component - it's the sort of thing where you send the cct diagram or board pattern to a manufacturer in China, and you get back 1000 of them for $0.10 ea + shipping (and if you send them the EEPROM data too, they'll probably program it for you for an additional $0.01! ;-). Somebody had it made, and somebody made if for them but, without any identifying marks or at least an idea of what it's from and what it's used for, it's impossible to say where you may get more.

(And, that said, it's the sort of thing the right hobbyist could make in an 30 minutes or so using an existing USB plug and a 24C16. Copying the data would take a computer with a parallel port and an additional 10 minutes - the 24C16 is not particularly fast, and each word takes 50ms or so to write ;-)
posted by Pinback at 8:43 PM on October 4, 2010

Response by poster: All, thank you for your comments. Although the question was not answered, you all have facilitated obtaining an answer from one of our component suppliers. In-other-words, you've pointed us in a good direction.
posted by strangelove at 2:52 PM on October 6, 2010