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TAS2505-Q1: TAS2505-Q1 diagnostic functions

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Replies: 4

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Part Number: TAS2505-Q1

Dear all

          I want to ask some questions for TAS2505-Q1,

        It has the following below diagnostic functions:
– Output-to-GND Short
– Terminal-to-Terminal Short
– Output-to-Power Short
– Over Temperature

              so i want to know  Can this device diagnose the state of the open circuit?

              if have no this diagnostic function, how can I design  this diag function or no good way to check it? 

please help me to confirm it。

Clarion-hejun

  • Hi, Clarion-hejun,

    My colleague will check this and will provide an answer as soon as possible.

    Best regards,
    Luis Fernando Rodríguez S.

  • Hello Clarion-hejun, 

    The TAS2505-Q1 does have Short-Circuit Protection which determines if there is a short to ground, power, or between terminals as you stated. 

    Additionally external diagnostics can be added to your design. We have a TI Design that does exactly this, TI Designs: TIDA-01529 Cluster and eCall Audio With Diagnostics Reference Design

    Please let me know if you have any additional questions. 

    All the best, 

    Carolina Gomez

  • In reply to Caro Gomez:

    Dear Carolina Gomez

            Thank  you for your help, I had added the open detector circuit copy of one in the TIDA-01529 Cluster and eCall Audio With Diagnostics Reference Design. ..like this below

            But I don't understand that   if there is a speaker connected and there is no fault, then the voltage divider will be approximately 1.2V.

           How calculate the ADC voltage 1.2V?

           Sorry, by the way,  According  to data sheet(Automotive Diagnostics) is below description :

           The TAS2505 has a short-circuit protection feature for the  speaker drivers,which is always enabled to provide protection.

      The output condition of the ........

             so I confused that  

    this protects outputs against short to ground,

    short to supply and short between output terminals.  It can be protected by itself(TAS2505-Q), But it can not do diagnostic ,is it right?

     Could you explain it?  Thank you very much...

    Clarion- hejun from China-Xiamen

  • In reply to user6190473:

    Hello Clarion-hejun, 

    I am not able to see your picture but I am assuming that you added Diagnostic Circuit #2. 

    A1: If there is no fault and the speaker is connected, the mosfet is biased to allow current to flow from SPKVDD through the speaker and eventually to the voltage divider that the ADC is connected to. This value is approximately 1.2 V but it depends on what speaker load you are using. This is a good circuit for open circuit detection because if there is no speaker connected, the current flowing from SPKVDD is not allow to flow to the ADC, resulting in ADC reading of 0 V. 

    A2: The TAS2505-Q1 does have short circuit protection as discussed earlier, in which it detects if there is a short to ground, power, or between terminals and the device will protect itself. If you would like you can add external diagnostics to determine which fault is happening as shown in our TI design. 

    Please let me know if I need to further elaborate. 

    All the best, 

    Carolina Gomez