uSD too bulky, what other storage is there?

[cdwijs]

Hi All,

I would like to build a very small datalogger. So small in fact, that I'm looking for something that can hold some (megabytes of) data, but is smaller than an uSD card.
I have found a chip that's 5x6mm, but I would like to know what other options are out there:
http://nl.farnell.com/spansion/s25fl164k0xnfi011/ic-memory-flash-64mbit-wson-8/dp/2363324

Kind regards,
Cedric

[exmadscientist]

What are your requirements (both minimum and goal)? Size and preferred interface are both important.

There are plenty of truly tiny memories out there, some even below 1 mm². But the really small ones can't store much: there's both a die size limitation and a minimum pin count for the interfaces on the larger (parallel) memories.

The 5 mm×6 mm size serial flashes are quite common, with options from many manufacturers. There are also several available in 2 mm×3 mm, but the selection there does decrease.

[ajb]

Note that with the larger serial memories, the minimum erasable size may get to be a bit large (4kbyte in the one you linked), so if you want to do a circular log (write until full, then start overwriting the oldest data) you will need to either give up an entire sector of data at a time or be able to hold a 4kB (or whatever) buffer in your MCU's memory before writing to the external memory.