• State Resolved
  • Locked Locked
  • Replies 6 replies
  • Subscribers 30 subscribers
  • Views 834 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

TAS5754M: Is it possible to disable TAS5754 going to standby with no I2S clock?

KesTam
Genius 9550 points
Part Number: TAS5754M

Hello Audio Folks, we have a customer encounter a pop noise at the beginning or end of playing sound output. The problem is due to TAS5754 is in in standby while the customer system in idle which has no I2S clocks. The pop is actually caused by the unbalance on the differential input of the amp from the internal DAC. Customer has put resistors between the DAC output to the amp input. I have managed to reduce/fix it by converting back amp differential input back to balance. But, customer still wants to keep the amp running even there is no I2S clocks in idle. This will perfectly fix the issue.

I have checked our data sheet. I try P0-R37 to ignore the I2S clock. But, this cannot prevent TAS5754 going to standby in no I2S clock. So, is there anyway to to it?

Regards,

Kes

  • 0
    TI__Guru 57800 points

    Hi, Kes,

    The I²S clocks must be active for this device in order to operate properly, could you please send me the configuration you used in register 37 to replicate it in the EVM?.

    Best Regards,

      -Diego Meléndez López
       Audio Applications Engineer 

  • 0 in reply to Diego Melendez
    TI__Genius 9550 points
    Hi Diego, for register 37, I try values like 0x7F and 0x3F. To check whether TAS5754 will go to standby with no I2S clock in EVM, it is very simple.

    You simply change the input to PSIA in PPC2 GUI. If you don't really hook up PSIA from AP, there will be no I2S clock to the IC. You will see TAS5754 stops PWM output which means a standby. If you change the input back to USB or Optical, you will see TAS5754 will output PWM again.

    I have tried different register values to see whether TAS5754 can keep PWM output in switching the input to PSIA. But, unfortunately, I cannot find a register setting so for.


    Regards,
    Kes
  • 0 in reply to KesTam
    TI__Guru 57800 points

    Hi, Kes,

    Thanks, I already tried a similar configuration in the EVM and external PSIA interface from AP, but just wanted to know the exact register settings you tried for R37. It seems that when the amp ignores the clock detection (write 0x64 to Register 37), the outputs won't be turned off when I²S inputs are removed as long as Master clock is still running. Could you please try this in your EVM?

    Best Regards,

      -Diego Meléndez López
       Audio Applications Engineer

  • 0 in reply to Diego Melendez
    TI__Genius 9550 points

    Hi Diego, thanks. I will try but need to wait till next Monday.

    Regards,

    Kes

  • 0 in reply to KesTam
    TI__Genius 9550 points
    Hello Diego, I have tried. As you said, writing reg 37 with 0x64 can keep PWM output for no BCLK and LRCLK. But, it still has issue with no MCLK. So, is there any setting which is also able to keep PWM output even with no MCLK?


    Regards,
    Kes
  • 0 in reply to KesTam
    TI__Guru 57800 points

    Hi, Kes,

    Unfortunately, the TAS5754M requires Master clock to drive the internal circuitry, if MCLK is not provided, the outputs of the amplifier will be turned Off. 

    Best Regards,

      -Diego Meléndez López
       Audio Applications Engineer