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Original question:

SN65176B: Die topology

SN65176B: Current consumption is not according to the datasheet in some batches.

Héctor Vitales
Prodigy 10 points
Part Number: SN65176B

Hello, 

I think we have counterfeit pieces for next reasons:

- In some batches the current consumption of this chip is 17mA (no communication activated)

- In other batches, the current consumption is 1mA (no communication activated)

- I have done different methods to confirm these last two affirmations. 

- Both chips are working "fine", or at least, it seems they do. They are communicating well in short distances.

- Issue: This different current consumption is causing fault in our test equipment in factory due to the behavior is different from the original chip, 17mA of current consumption is our specification in the test equipment. So currently it's a very critical point to solve. 

- I attach some pictures of good and bad samples.

- Could you confirm if these lot codes are according to Texas Instruments? Thanks in advance.

Good ones serigraphy:

Sample 1:

First raw = 65176B

Second raw = 75M

Third raw = A92VG4

Sample 2:

First raw = 65176B

Second raw = 88M

Third raw = A031G4

Bad ones serigraphy:

Sample 1:

First raw = 65176B

Second raw = 2AK

Third raw = DC4KG4

Sample 2:

First raw = 65176B

Second raw = 29K

Third raw = C7HVG4

  • +1
    TI__Guru 52022 points

    Hi Héctor,

    So in general lower than expected current with no functional failures isn't usually a super large concern - we don't spec a minimum unloaded device current.

    That being said:

    Good Sample 1: Legitimate Device 

    Good Sample 2: Does not show up in our system under correct device* (potentially counterfeit - more info here:  https://www.ti.com/support-quality/quality-policies-procedures/anti-counterfeit.html )  

    Bad Sample 1: Legitimate Device

    Bad Sample 2: Legitimate Device. 

    So it does seem like you may have a counterfeit device - but its not the one you were concerned about - and I think I know what's going based on your results - potential counterfeit aside.

    1. There are two versions of this device that exist - your good sample 1 is older material - the original die of the device. The two suspect devices are using the newer version of the die. 

    2. Since when we released the new die a couple years ago there are multiple variants of the device that exist - with only one datasheet. So how the changes get implemented onto the datasheet really are going to reflect boundary conditions. I.e. the typical values may shift and not show in the datasheet as long as you can apply the same boundary conditions - i.e. max and min spec changes will always be reported - typical changes being reported is more variable as the typical value is already variable based on use case - so it is possible that the new die is less power intensive (which is a good thing - as tens of mA's with no load  is not great performance in general) but since its still bounded by the max condition of the datasheet that spec most likely didn't change.  So the both versions are bounded by the same limiting values - but typical performance can be different and in this case - it seems to be better. 

    3. We don't spec a minimum supply current so from TI's perspective no failure has occurred and based on the history of this device the differences are more or less in line with what to expect.


    That being said - if you do find functional failures please don't hesitate to inform as there could be another issue.

    Please let me know if you have any other questions.

    Best,

    Parker Dodson

  • +1 in reply to Parker Dodson
    Prodigy 10 points

    Parker, many thanks for your clarifications. Very useful information, I think all is clear and we can act according to this.

    Thanks and have a nice day,

    Regards

  • 0 in reply to Parker Dodson
    Prodigy 10 points

    Hello again Parker,

    According this change that was done a couple of years ago, is it possible to get the "Product Change Notification" of this change? Or some official document related?

    I mean, this change is affecting to our production so we need to know how we can detect these chips before entering in our production line.

    At the end, we have same part number but different behavior.

    Or maybe with the lote code, is it possible?

    Thanks in advance,

    Regards.

  • 0 in reply to Héctor Vitales
    TI__Guru 52022 points

    Hi Héctor,

    So each PCN is generated from a template - and I only have the template - so I don't have an official document to send you. That being said please see below for information that should be able to allow you to detect these new devices.

    See below sample shipping label on product boxes (this isn't the exact same part - but follows the same format):

    For this specific part:

    Label 20L = CSO: RFB

    Label 21L = CCO: USA

    Label 22L = ASO: MLA

    Label 23L = ACO: MYS

    Label 2P = REV:   (it is blank - like above example for new die) 

    This is the best way to tell the devices apart as part markings are not going too be the most reliable to tell apart devices - as the way you'd be able to tell is through the year marking (i.e. parts after 2021 are new die)  - which is only 1 digit  - and this part has existed for almost 40 years so there could be differences in part marking over time and our current system could have "repeat" codes for devices made 10 years apart from each other. 

    Please let me know if you have any other questions and I will see what I can do. 

    Best,

    Parker Dodson