• State TI Thinks Resolved
  • Locked Locked
  • Replies 13 replies
  • Answers 5 answers
  • Subscribers 32 subscribers
  • Views 229 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TAS6424EQ1EVM: TAS6424EQ1EVM Line-out DC Load Diagnostics

He Siang Deng
Prodigy 30 points
Part Number: TAS6424EQ1EVM
Other Parts Discussed in Thread: TAS6424E-Q1

Hi E2E Support Team,

Recently, I tried to use DC Load Diagnostics on TAS6424E-Q1 and measured the maximum detectable resistance.

I realized when the resistance is larger than 7.65k ohm, TAS6424E-Q1 would show open-load on PPC3, but in TAS6424E-Q1 Doc (P.10), the maximum open-load resistance is 6k ohm.

Is it would be affected by temperature or other reasons?

Best regards,

Jeffery.

  • 0
    TI__Genius 16820 points

    Hi Jeffery,
    You can refer to Figure 9-7. DC Load Diagnostic Reporting Thresholds, 6Kohm is the threshold value, if load is in the value, device can guarantee report normal.

    Regards,
    Derek

  • 0
    Prodigy 30 points

    Hi Derek,

    Thanks for your answer~

    Are the values correct in the figure?


    I have another question.
    Will the DC Load Diagnostics Threshold be changed after using it for a long time, in a high-temperature environment, or other affected?
    Does TI give any guarantee or any other limit?

    Best regards,
    Jeffery.

  • 0 in reply to He Siang Deng
    TI__Genius 16820 points

    Hi Jeffery,

    Your comments on figure are most correct, but the Lineout maximum value is not correct. TI only guarantee that Line out load is normal if load is smaller than 6Kohm.

    For the tolerance question, the values in datasheet spec can cover high and low temp. environment.

    Regards,

    Derek

  • 0 in reply to Yanming Gong
    Prodigy 30 points

    Hi Derek, 

    I think this figure would be correct.


    Here has another related issue.

    I used to use 14V as the PVDD, and the DC diagnostics thresholds are close to the datasheet value, but after I changed the PVDD from 14V to 5V, the value would be different.

    The most different thing is the OL max when line-out is disabled.

    1.PVDD=14V, Line-out disabled, OL Max measurement=70ohm

    2.2. PVDD=5V, Line-out disabled, OL Max measurement=390ohm

    Is this correct?

    Best regards,

    Jeffery.

  • 0 in reply to He Siang Deng
    Prodigy 30 points

    Is it means the voltage would affect the tolerance?


    What if used for more than five years or ten years? Will the tolerance get worse?

  • 0 in reply to Yanming Gong
    Prodigy 30 points

    And I also find this information in datasheet.


    The OL detection threshold is 40~70 ohm, but the datasheet said the external amp resistance should be between 600 ohm and 4.7k ohm.
    If our external amp resistance is 300 ohm, can this external amp be used on TAS6424E-Q1?
    I tried 300 ohms on the TAS6424E-Q1 EVM, which can be detected as the line-out. So I think it can be used, but I do not know if it will have any potential risk.

    Best regards,

    Jeffery.

  • 0 in reply to He Siang Deng
    TI__Genius 16820 points

    Hi Jeffery,

    TI Qualification can guarantee the threshold can meet datasheet spec at high/low temp. and high/low voltage, life time test.

    Usually Line out is for external AMP application. The external AMP input impedance is usually >600ohm. 

    If you connect 300ohm load, open load will be report.

    Regards,

    Derek

  • 0 in reply to Yanming Gong
    Prodigy 30 points

    Hi Derek,

    This is the result that I use 4 ohms for channel 1~3 and use 300 ohms for channel 4 when the "line-out enable diagnostics" is enabled.

    Is it means 300 ohms can be detect?


    Regards,

    Jeffery.

  • 0 in reply to He Siang Deng
    TI__Genius 16820 points

    Hi Jeffery,

    I would like say that I can not guarantee any data which is out of datasheet spec.

    600ohm is data that TI can guarantee.

    Regards,

    Derek

  • 0 in reply to Yanming Gong
    Prodigy 30 points

    Hi Derek,


    I want to ensure this result means channel 4 detects the external amplifier, right?

    .

    When the impedance between 70~600 ohm and line-out diagnostics is enabled, what should it be?

    My experiment will always report that the line-out is detected, not open-load.

    .

    According to the figure10-1, it said the external impedance should be between 600~4.7kohm.

    But the spec in the datasheet said Line-output 6k ohm. What is it means?


    .

    Regards,

    Jeffery.

  • 0 in reply to He Siang Deng
    TI__Intellectual 2990 points

    Hi Jeffery.

    Derek is out of office today, he will reply you when he is back.

    BR. 

    Wei Qiu.

  • 0 in reply to He Siang Deng
    TI__Genius 15440 points

    Hi Jeffery

        In the table, the 6Kohm means the load diagnostic can test out the largest value is around 6Kohm. Larger than this one will be reported as open-load. The load diagnostic range leaves some margin for real using range.   

  • 0 in reply to He Siang Deng
    TI__Genius 16820 points

    Hi Jeffery,

    The spec on table is correct. You should refer the table spec. Thanks!

    Regards,

    Derek