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a problem about how to use TAS5731EVM

Other Parts Discussed in Thread: TAS5731

Dear all

This is Charlie from China.

I have applied TAS5731EVM with MC57XX-PSIA board and trying to run them. I have 2 questions.

1.  I connected them by 2.1 mode according to the user's guide found in TI's website.

Then I use my smart phone as a coaxial input but no output was found.

I also tried 2.0 mode, sitll no output.

I hadn't  connected the board to PC by USB I/O by then. Is that the problem ? or other problems ?

2.  I installed the GUI and tried connecting the board with PC , but failed to load.

 

Any suggestions for the problems ?

thanks and best regards

 

  • Hello Charlie,

    Please take a look to my comments.

    1.- In order to use the analog input, some jumper adjustments in MC57xx are required:

    • Select ADC in JP4 and JP5 (short on pins 1 and 2).
    • Audio CLK jumpers (JP6-JP10) should be connected with pins 1 and 2 tied. 
    JP2 and JP3 will limit the input voltage:
    • IN: LIN/RIN = 1Vrms MAX.
    • OUT: LIN/RIN = 2Vrms MAX. 

    Coaxial connection is used as digital audio source, so if you are using your smartphone with RCA cable, you should use Analog inputs.

    If you are not connecting the MC57xx to PC, then I suppose that you are using an external I2C interface to program the device, otherwise the device will not work because it needs to be configured.

    2.- Could you be more specific on what you mean with "failed to load"?.

    In order to connect the TAS5731EVM, you need to run the GUI, in "Properties" side window you can select the device. By default, TAS5731 is selected. Then, connect the EVM by selecting Target >Connect. 

    Environment variables should be correctly configured for this device, you can check how to do this in the TAS5731EVM Evaluation Module User's guide.

    Best Regards,

      -Diego Meléndez López
       Audio Applications Engineer

  • Dear Mr.Diego

    Thanks very much for your detailed comments.

    I ran the GUI to connect the TAS5731EVM by selecting Target>Connect.
    And I also connected JP4-JP10 to support Analog input.
    Now the waveform of pin 1 is strange, it seems not like a analog output. I also checked the waveform of pin22 and found that digital input is OK.
    So I think maybe TAS5731 is not working normally.
    Any suggestions ? And how can I know whether the device was programed successfully.

    Sorry to brother you again, your kindly reply will be appreciated.

    best regards.

    Charlie
  • Hello Charlie, 

    TAS5731 is a class-D amplifier, so if you take a look at pin 1 of the device, you will see a PWM. Class-D amplifiers requires an output filter to reconstruct audio signal, so you need to check the signal after the filter inductors (in the A, B, C or D terminals of the EVM). 

    For a correct initialization using the GUI, you need to: Connect the device > Exit shutdown mode > Unmute the master volume > Adjust the volume. 

    Best Regards,

      -Diego Meléndez López
       Audio Applications Engineer

  • Dear Mr.Diego

    Thanks very much for your useful comments.
    Finally I got the output . And still there are 3 questions which need your kindly support.
    1. The output of SE-A terminal is max 2V.(Vin=18V, RL=4Ω) Is it correct ?

    2.The waveform of output is different from the value I set in the register.

    3.The output disappeared while I was testing. Then I checked the MC57XXPSIA board and found that the 5V supply for system power was pulled down to 5V—>1.87V. When I separated the two board, it turned back to 5V. So I think there is something wrong with TAS5731EVM. I don't know why...(PVDD supply is OK).

    Could you please help to check the problem ?

    Thanks and best regards.
    Charlie
  • Dear Mr.Diego

    Sorry to bother you so many times.
    We still have not found the reason.
    So could you please help to check the problem ?
    Thanks and best regards.
    Charlie
  • Hello Charlie, 

    Sorry for the delay, I suppose you configured the device in 2.1 mode (2xSE +1 BTL), is this correct?. I have some questions:

    Can you please describe the type of waveform you are obtaining in the output and the one you are using as input?, do you have any scope captures?.

    You mention a register, could you please provide the value you are writing and the addres of the register?. 

    After the output disappeared, did you connected back the EVM and check if it is still working?, Do you noticed something strange like a short or heat of the part?.

     Thanks and Best Regards,

      -Diego Meléndez López
       Audio Applications Engineer

  • Dear Mr.Diego

    Thanks for your hint. I checked the pins of TAS5731 chip and found that AVDD is short to GND.
    Besides, the LDO(TPS76733) output is also short to GND.
    So I think the two boards are both burnt.
    I am going to contact TI's local office to solve the issue.

    Thanks you very much for your support.
    best regards.
    Charlie