SMD marking 2L805 - SPI eeprom?

[deanclaxton]

I have a part on a board which I suspect is a SPI eeprom, however I havent been able to find a datasheet. Its an 8 pin package marked as 2L508 2L805 and I believe it has  WP on pin 3 ("WP"" is marked on the sikscreen on a test pad wired to this pin so that is a pretty good hint!).

The chip is storing EDID information on a laptop LCD panel and I'd like to update the contents but need to firstly confirm the model to check that my programmer supports it. I''ll possibly have to remove it from the board to program it. I believe that only the clock and MISO are connected through to the laptop - thus when attempting to reprogram it using from the computer, the information is not stored as MOSI is not wired outside of the panel (there is a test pad on the board for this pin that they likely use to program it in the factory).

Any thoughts what it might be? I was thinking perhaps 25L080 but that is a lot larger than necessary for EDID. 25L010? That will be my first try if I cant identify it before I try program it.

[fzabkar]

Are you sure that's "2L508" and not "25L08" or "25L080"? BTW, I thought EDID chips were microwire, not SPI. :-?

[deanclaxton]

Its definitely marked as 2L508, with WP on pin 3. I think it's SPI but not 100% sure.

[fzabkar]

Its definitely marked as 2L508, with WP on pin 3. I think it's SPI but not 100% sure.

Perhaps only those EDID EEPROMs which are accessible via a monitor's external port require i2c?

[deanclaxton]

I initially thought it was I2C, but they all seem to have WP on pin 7. I might just have to take it off, solder it to a board and give it a shot.

[DavidAlfa]

Really? No picture? 

[deanclaxton]

I managed to take a photo from my phone with a backlight to light the SMD code. Silkscreen would also indicate that this is a SPI device. I suppose I was just hoping to identify the device before I randomly try program it, but it does seem to be a 25L0x series device from the pinout. Resistors are 0402, cap must be 0201. Its quite a small package.

[fzabkar]

It's "2L805", not "2L508".

[deanclaxton]

Sorry - I knew that and somehow typed the wrong code without realising I had. 2L805 yes. I havent been able to find what it is.

[fzabkar]

FWIW, I have these SPI flash chips in my SSD/HDD database:

W25X20CLUXIG, Winbond, 2.5/3/3.3V 2M-BIT SERIAL FLASH MEMORY WITH 4KB SECTORS AND DUAL I/O SPI, marking 2Hxxx & 0Gxxxx, USON 2x3-8:
http://chip.tomsk.ru/chip/chipfile0-x.nsf/all/49D18EA25FB19D5A4725822D00642029/$File/w25x05cl_10cl_20cl%20revc_c03_20120801.pdf
http://chip.tomsk.ru/chip/chipfile0-x.nsf/all/4B70D1CEE983C2614725822D00642E89/$File/w25x20cl_revf%2020150806.pdf

W25Q80EWUXIE, Winbond, 1.8V 8M-BIT SERIAL FLASH MEMORY WITH DUAL/QUAD SPI & QPI, marking 8Lxxx & 0Exxxx, USON 2x3-8:
http://chip.tomsk.ru/chip/chipfile0-x.nsf/all/FA65C5CB65A1BD864725822D00641FEF/$File/w25q80ew%20revi%2008222017%20sfdp.pdf

Therefore, I feel confident that you have a 2Mbit Winbond SPI flash in a USON 2x3-8 package, probably 1.8V.


I found it:

W25Q20EWUXIE, Winbond, 1.8V, 2M-BIT, SERIAL FLASH MEMORY WITH 4KB SECTORS, DUAL AND QUAD SPI, marking 2Lyww + 0Exxxx, USON-8:
https://www.winbond.com/resource-files/w25q20ew_revi%2008222017%20sfdp.pdf

[deanclaxton]

Thanks I will see if I can wire it to my programmer and try reading it - perhaps using the test points else mounting it on an adapter.

[deanclaxton]

Looks like Microchip to a 25XX010A that is available in a 2 x 3 TDFN and of more likely capacity of 1Kbits - could be a clone of that too I suppose.

[fzabkar]

ISTM that there must be a reason that the designer used a 2Mbit part. Perhaps it stores some firmware, not just EDID? Anyway, a dump will tell.

[deanclaxton]

Oh - I see - yes that must be the part (W25Q20EWUXIE) - great find! The second line on the chip is 0E41A7 so that perfectly matches the W25Q20EWUXIE.

Thank you for your help with this   

[amyk]

ISTM that there must be a reason that the designer used a 2Mbit part. Perhaps it stores some firmware, not just EDID? Anyway, a dump will tell.

Yes, 256KB is ridiculous for just EDID. Might contain firmware for the OSD MCU too.