ATML H04802C Serial EEPROM? - UK Vintage Radio Repair and Restoration Discussion Forum

unitelex · 4th Jan 2023, 9:30 pm

I have some of these 8 pin SOIC devices in some thermostats and they seem to have failed. I can find only some vague references to them in a Google search. I assume they are long since obsolete.
From the circuit connections it seems to be a 2 wire or 3 wire serial type with a pinout similar to a more recent 24C02 device, however I tried a 24C02 and it does not work.

I would like to replace them with a modern compatible equivalent if one exists, I cant change the software to suit a modern one if its protocol is different though. It might be possible to emulate its function with a tiny microcontroller but that could be more effort than its worth.

A start would be to have a data sheet for this H04802C - presumably from Atmel (now Microchip).

Does anyone recognise this part, have its datasheet or other information?
I will also try asking Microchip... but not all semi manufacturers are helpful with obsolete part information other than advising to redesign to use their latest production types...

Thanks
Chris

-ADBeta- · 5th Jan 2023, 10:27 am

Hi. Can you post a picture of the chip so we can see the whole marking to aid with context, H04802C seems to be a slightly malformed standard EEPROM marking.

Here is a link to Mouser to search for your part. Hopefully it isn't so outdated as to not appear. Hope this helps https://www.mouser.co.uk/c/semicondu...%20%2F%20Atmel

4th Jan 2023, 9:30 pm	#1
unitelex Hexode Join Date: May 2005 Location: Greater Manchester, UK. Posts: 496	ATML H04802C Serial EEPROM? I have some of these 8 pin SOIC devices in some thermostats and they seem to have failed. I can find only some vague references to them in a Google search. I assume they are long since obsolete. From the circuit connections it seems to be a 2 wire or 3 wire serial type with a pinout similar to a more recent 24C02 device, however I tried a 24C02 and it does not work. I would like to replace them with a modern compatible equivalent if one exists, I cant change the software to suit a modern one if its protocol is different though. It might be possible to emulate its function with a tiny microcontroller but that could be more effort than its worth. A start would be to have a data sheet for this H04802C - presumably from Atmel (now Microchip). Does anyone recognise this part, have its datasheet or other information? I will also try asking Microchip... but not all semi manufacturers are helpful with obsolete part information other than advising to redesign to use their latest production types... Thanks Chris

5th Jan 2023, 10:27 am	#2
-ADBeta- Triode Join Date: Jan 2023 Location: Birmingham, West Midlands, UK. Posts: 19	Re: ATML H04802C Serial EEPROM? Hi. Can you post a picture of the chip so we can see the whole marking to aid with context, H04802C seems to be a slightly malformed standard EEPROM marking. Here is a link to Mouser to search for your part. Hopefully it isn't so outdated as to not appear. Hope this helps https://www.mouser.co.uk/c/semicondu...%20%2F%20Atmel