24LC512 vs. 24LC515

Bobb Fwed

I am curious what are the difference between the 24LC512 and the 24LC515 EEPROM ICs? They are both 64Kx8bit (512kbit). They seem to have different current ratings. The 512 has a 128-byte page write buffer, but the 256 (comes with Prop demo boards) and the 515 both have 64-byte page write buffers. But the 515 seems to be more expensive.

I have some 24LC515s and they work great.
What benefits does one have over the other? I am assuming both are compatible with the Propeller.

I am guessing the 128-byte page buffer can speed up writing info (when over 64-bytes need to be written). But then can more than 64-bytes be read at once (or is it just writing that is ever limited)? I don't quite know enough about EEPROM design/use to figure this one out.

EDIT: attached datasheets for reference.

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April, 2008: when I discovered the answers to all my micro-computational-botherations!

Post Edited (Bobb Fwed) : 8/31/2009 11:46:25 PM GMT

Erik Friesen

This is typical of Microchip datasheets. The difference is probably somewhere there.

I would go with the 128 page write as it can take 5ms per page, which totals 2.6 seconds on a complete write. The prop won't see the difference programming it I doubt, because I'd guess it uses a 64 byte/page write.

Tubular

Good question. My *guess* is it may be to do with the number of I2C addresses occupied on the I2C bus. The 515 might occupy 2 sequential addresses? (Datasheets identify 4 vs 8 cascadable devices). I think this aspect was also recently discussed in context of the 24xx1024 parts (Atmel vs Microchip)

The Microchip selector states 515's are not available Pb-Free (see screenshot), but the datasheet contradicts this.

tubular

Bobb Fwed said...
I am curious what are the difference between the 24LC512 and the 24LC515 EEPROM ICs? They are both 64Kx8bit (512kbit). They seem to have different current ratings. The 512 has a 128-byte page write buffer, but the 256 (comes with Prop demo boards) and the 515 both have 64-byte page write buffers. But the 515 seems to be more expensive.

Phil Pilgrim (PhiPi)

Comparing the two data sheets, it's hard to fathom why Microchip even bothers with the '515. It uses only two address lines (A0 and A1) vs. three for the '512, has a smaller write buffer, and is more expesive. By comparison to the '512, I don't see much to like about it. I can only guess that it's an interim version that predates the '512 and that it's only being kept in their product line for legacy reasons.

-Phil