Question regarding date codes on MC9S08GT8A

[anze1]

Hello!

I have a question regarding the date codes market on the MC9S08 microcontrollers.

We use these microcontrollers on a low power product (sub 2mA). 

Our latest batch has a problem in that it's usage is about 300-500uA higher than all of our older batches.

We found that replacing the mcu with one from an older batch solves the problem. 

The only difference on the mcu's are the production codes. As i have not found any information on how to read/translate them, i am asking for your help.

The good mcu's are marked as follows:

MC9S08GT8A

CFBE 2M70C

CTPM1639L

and

MC9S08GT8A

CFBE 2M70C

CTNJ1538U

The ones that are not ok are marked:

MC9S08GT8A

CFBE 2M70C

CTAB0643

(pictures attached)

Am i correct in my assumption that the marking CTNJ1538, the 16 means the year of production (2016) and the 39 means week 39?

Would that mean that the problematic mcus are from 2006 week 43?

Any help would be greatly appreciated!

Best regards, 

Andy

[vicentegomez]

yes you are correct the 0643 is 2006 week 43

regards

Vicente Gomez

[anze1]

Thank yo for your quick reply!

We foud that a newer batch of mcus does not have the same fault, although they are also very old (prod. number CTAB0730). Is there a way to figure out if there were any differences between these production runs?

It seems that our supplier received some new old stock mcus, as i checked some of our earliest products and the oldest production date i found was marked CTKE1316. 

On another note do all the MC9S08GT8A share the same mask (2M70C)?

Thank you again for your help, we were able to isolate the problem to the mcu on about 600pcs of pcbs that can now be salvaged. 

[vicentegomez]

On another note do all the MC9S08GT8A share the same mask (2M70C)? 

Yes, I believe that the first mask never went to the market.

Please let me know if you have more questions

have a good day.