# What kind of IC is “ATMLU324” “16B 1” “Z8J0534B”?

I recently bought what I thought it would be an ATtiny85. After a few unsuccessful tests, I discovered (guess what?) true ATtiny85 had "ATtiny85" printed on it, like this one:

Mine is this one:

The printing says:

ATMLU324
16B 1
Z8J0534B


I searched for a datasheet, but all I found was datasheet sites searching for it too. What is this chip?

• Where did you buy it? – marcelm Mar 31 '17 at 13:11
• @GabrielRado So, with > 95% probability this is a counterfeit or garbage, or something that left the factory in ways it shouldn't have, for all we can tell, OR this is really a custom Atmel product that they made for a bigger customer and they had overstock and sold that. And you bought something that might work like an Attiny85 in some ways, but not in some others. These ICs costs cents new from large distributors. I recommend throwing yours away. You've been scammed. Don't buy electronic components from questionable sellers. – Marcus Müller Mar 31 '17 at 13:19
• Oh by the way, the crime here is called fraud (against you), and counterfeiting (against Atmel). Atmel might be nice to you if you tell them. – Marcus Müller Mar 31 '17 at 13:21
• "Wanted organ for our church, got a package of strange meat. Would not buy again." – rackandboneman Mar 31 '17 at 15:28

It looks for all the world like an Atmel AT24C16B, a 16kbit two-wire serial EEPROM chip.

In particular, page 14 of the datasheet has this diagram explaining the markings on the DIP version of the chip:

                      Seal Year
|  Seal Week
|   |   |
|---|---|---|---|---|---|---|---|
A   T   M   L   U   Y   W   W
|---|---|---|---|---|---|---|---|
1   6   B       1
|---|---|---|---|---|---|---|---|
* Lot Number
|---|---|---|---|---|---|---|---|
|
Pin 1 Indicator (Dot)

Y = SEAL YEAR             WW = SEAL WEEK
6: 2006  0: 2010          02 = Week 2
7: 2007  1: 2011          04 = Week 4
8: 2008  2: 2012          :: : :::: :
9: 2009  3: 2013          :: : :::: ::
50 = Week 50
52 = Week 52


Maybe you were simply sent the wrong part by mistake. Or maybe the seller tried to scam you with a cheaper (or counterfeit) part.

• ... and then the seller mysteriously disappeared from the market place they sold the wrong chip on? While I value your belief in the good in mankind... – Marcus Müller Mar 31 '17 at 13:28
• @MarcusMüller Or they went out of business because they kept sending customers incorrect parts. You can't just conclude malice from the information we have now. – marcelm Mar 31 '17 at 13:34
• @marcelm fair point, but I'm trying to think of likelihoods here, and that tells me that parts labeled as something else sold from a Argentinian marketplace website with a Brazilian domain selling chips with exactly that marking are available from aliexpress with a seller that disappears isn't a good basis for assuming they did a mistake – Marcus Müller Mar 31 '17 at 13:44
• @MarcusMüller Fair enough. And I agree it's certainly possible that it was a scam. No way to be sure though :) – marcelm Mar 31 '17 at 14:39
• @marcelm high five :) full agreement – Marcus Müller Mar 31 '17 at 14:41

First of all, I believe it should read ATMLU924.

There are multiple sites online that suggest these are knock-off serial eeproms, see

You could try hooking these up and see if you can still use them as memory. However, if they were advertised as ATtiny85, it's likely that somebody scammed you, unfortunately.

• I went by the picture OP posted. Compare the 9 with the 3 further down. – FRob Apr 1 '17 at 10:18
• Fair enough, they do look slightly different. You may be right. – marcelm Apr 1 '17 at 12:35

Multiple pictures with that same code show up on websites like Alibaba, claimed to be an attiny. It's a counterfeit of some kind, maybe it is an attiny inside and will work like one, maybe not. Only way to find out is to try to program it.

• and not even that would prove it works like an Attiny – it might misbehave in strange ways. – Marcus Müller Mar 31 '17 at 13:20
• @marcusmüller definitely, it could even be an attiny that failed QA and got stolen instead of destroyed/recycled. Whatever it is, it's probably not worth using – mbrig Mar 31 '17 at 13:24