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Quality of IC data sheets

Gary Lynch
Expert 1310 points

TI data sheets used to be used to be a paragon for the rest of the semiconductor industry to emulate, but now I am seeing the standards slip.

This week a couple of our developers got into an argument over the AEC status of a TI voltage reference on a new product, one claiming that the TL4050B25QDBZR was AEC qualified and the other that it was not. The initial assumption was that the 'Q' always means AEC-Q in TI part numbers.

If you consult the data sheet the first thing you find out is that there are separate data sheets for the AEC and non-AEC parts. The second thing you discover is that the string "AEC" does not appear anywhere in TI's data sheet for the AEC part. (Mouser claims this P/N is AEC qualified, but TI does not.) If you want to know what a particular symbol in a given part number means you have to parse a table (For the non-AEC part the table runs over 3 pages), and figure it out for yourself.

Once upon a time, you could count on TI (and most other semiconductor manufacturers) to explain their part numbers in the manner I depict below in the data sheet (I had to reverse-engineer this, as it is not in the data sheet).

    TL 4050 B 25 Q DBZ R Q1
    -- ---- - -- - --- - --
    |    |  | |  |  |  | |
    |    |  | |  |  |  | +--- AEC-Q status
    |    |  | |  |  |  |        blank: non-AEC
    |    |  | |  |  |  |        Q1:    AEC-Q100
    |    |  | |  |  |  |
    |    |  | |  |  |  +----- Shipping package:
    |    |  | |  |  |           R: Reel of 3000
    |    |  | |  |  |           T: Reel of 250
    |    |  | |  |  |
    |    |  | |  |  +-------- Package:
    |    |  | |  |              DBZ: SOT-23-3
    |    |  | |  |              DCK: SC-70
    |    |  | |  |
    |    |  | |  +----------- Temp range:
    |    |  | |                 I:  -40 to 85 °C
    |    |  | |                 Q:  -40 to 125 °C
    |    |  | |
    |    |  | +-------------- Nominal output voltage
    |    |  |                   10: 10 V
    |    |  |                   25: 2.5 V
    |    |  |                   40: 4.096 V
    |    |  |                   50: 5 V
    |    |  |               
    |    |  +---------------- Voltage tolerance:
    |    |                      A: 0.1% initial, 50 ppm/°C tempco
    |    |                      B: 0.2% initial, 50 ppm/°C tempco
    |    |                      C: 0.5% initial, 50 ppm/°C tempco
    |    |
    |    +------------------- Shunt voltage reference
    |   
    +------------------------ TL series

With this breakdown it easy to see that 'Q' appears twice and that only the second one means AEC qualified.

Without it the careful developers get slower and the fast developers make mistakes. Life for the developer gets tougher.

Has anybody heard an explanation for this downgrade?

  • 0
    TI__Mastermind 19580 points
    Hi Gary,

    I can understand the frustration with this. Before having AEC100 devices, the Q was just a temperature designation and it has cause confusion because AEC100 is a "Q1" suffix and they both share the "Q". Going forward into new datasheet revisions I have begun to add nomenclature breakdowns such as the one below. Hopefully you will see this in future datasheet and datasheet revisions. I do not have an answer on why certain datasheets have not been updated in a long time or are "downgraded" but one way to fix this is to bring it up to our attention with TI support.
    Make sure to be on the Q1 folder to ensure AEC100.
    www.ti.com/.../tl4050b25-q1

    -Marcoo
  • 0 in reply to Marcoo Z
    Expert 1310 points

    Marcoo,

    Thanks for the follow-up.  I hope the idea catches on.

    I would also emphasize the importance of citing the AEC standard on the data sheets of parts that meet one.  Many manufacturers abuse the word "automotive" and apply it when the part only works up to 125 °C or has passed 1 AEC test.  I wrote a guideline for junior engineers a couple years back and told them that if the string "AEC" did not appear on the data sheet (we can only use AEC-qualified parts) they should not waste time trying to find other proof.