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TPA3220EVM: Fault pin voltage of TPA3220

Part Number: TPA3220EVM

Dear Sirs,

My customer asked us about voltage of FAULT pin for TPA3220.

Because the voltage of FAULT pin on board made by him is 5 V.
Then he confirmed it with TPA 3220 EVM and it was 5 V.

In the data sheet of TPA3220, the voltage of the FAULT pin is described as Typical 3.3V(Max3.6V).

Then I confirmed it again, but on the TPA 3220 EVM the FAULT pin voltage was 5 V.
I cheked circuit diagram of TAP3220EVM, It turned out that this was pulled up to 5 V externally circuit.
In the other TAP324x, TPA325x EVM circuit diagram, the external pull-up is 3.3V.
What is the difference?
In the data sheet, all the voltages on the FAULT pin are Typical 3.3 V (max 3.6 V).
From this data sheet, 5 V is out of the range of recommended specification.

1. Is the voltage specification of the FAULT pin of TPA 3220 correct?
2. Why is the FAULT pin voltage of TPA 3220 EVM set at 5 V?
Is this a problem?

Please let me know reply to above questions.

Best Regards,

Y.Hasebe

  • Hasebe-San,

    The FAULT pin is 5V or 3.3V tolerant, please see the abs max table in the datasheet:

    Regards,

    -Adam


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  • In reply to Adam Sidelsky:

    Hello Adam-san,

    Thank you for your reply.

    I know abs max table in the datasheet.

    If abs max is 5.5 V, why is the VOH max of OTW / SHUTDOWN (FAULT) on page 8 of the data sheet 3.6 V?

    Please let me know this reason.

    Best Regards,

    Y.Hasebe

  • In reply to yoshiki hasebe:

    Hello Adam-san,

    I have an additional question.
    If abs max is 5.5 V,
    Is the OTW / FAULT pin of the TPA3220 internally pulled up to 5V?
    Is the specification of OTW / SHUTDOWN (FAULT) in the data sheet correct?

    Best Regards,
    Y.Hasebe
  • In reply to yoshiki hasebe:

    Yes it is correct.
  • In reply to Adam Sidelsky:

    Hello Adam-san,

    Thank you for your reply.

    If so, I think that the OTW / SHUTDOWN (FAULT) Specification in the data sheet is incorrect.
    I can not understand that the maximum value of VOH of OTW / SHUTDOWN (FAULT) in the data sheet is 3.6 V although it is pulled up to 5 V in Internal.
    Which one is correct?

    Best Regards,

    Y.Hasebe

     

     

     

     

     

  • In reply to yoshiki hasebe:

    Hasebe-San,

    According to the datasheet: "To reduce external component count, an internal pullup resistor to 3.3 V is provided on both FAULT and
    OTW_CLIP outputs."

    This is on page 24.

    Regards.

    -Adam
  • In reply to Adam Sidelsky:

    Hello Adam-san,

    Thank you for your reply.

    I already knew this comment of datasheet.("To reduce external component count, an internal pullup resistor to 3.3 V is provided on both FAULT and OTW_CLIP outputs.")

    This is also the same specification for the TPA325x and TPA324x series.

    The difference is Absolute Maximum Rating as follows.

    Ex.TPA3251D2

    Then in my customer prototype board and TPA3220EVM, the output of the Fault pin is 5.5V.

    Abs.Max of TPA325x, TPA324x series was 4.2 V as mentioned above.

    Please let me Know why the above device and the TPA3220 Fault pin Specification are different.

    Also, the external resistor for the LED of the TPA325x, TPA324x series EVM's Fault pin is pulled up to 3.3 V, but the TPA3220EVM pulled up the external resistor for the LED of the Fault pin to 5 V.

    Please let me know about this difference.

    TPA3220EVM_Schematic diagram

    TPA3251EVM_Schematic Diagram

    Best Regards,

    Y.Hasebe

  • In reply to yoshiki hasebe:

    Hasebe-San,

    Since the TPA3245, 3251, 3250, etc did not have 5V gate drive, we used 3.3V for the low voltage control and status outputs.

    The TPA3220 and TPA3221 have 5V gate drive and so we made all the control and status pins 5.5V compliant. They will trigger a HIGH at levels compatible with 3.3V logic or 5V logic. The TPA322x devices no longer use 3.3v because they already have the 5v internally generated and 3.3v is not needed.

    Regards,

    -Adam
  • In reply to Adam Sidelsky:

    Hello Adam-san,

    Thank you for your reply.

    I understand your comments.

    Therefore, I have a question again.

    I think that the Supecification of VOH of OTW / SHUTDOWN (FAULT) in the data sheet is incorrect.
    Please let me know the correct Specification.

    Best Regards,
    Y.Hasebe
  • In reply to yoshiki hasebe:

    The spec is correct.

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