• State TI Thinks Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 2 answers
  • Subscribers 30 subscribers
  • Views 300 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.

Original question:

Linux/TAS5733L: Volume table implementation registers

Linux/TAS5733L: Volume table implementation registers

Nikhil Sahu78
Prodigy 250 points
Part Number: TAS5733L

Tool/software: Linux

Hi Shawn,

I implemented the volume table using the register 0x07 values. But we are facing one random issue.

when we play the song and increasing the gain after the -6db (-6 to 24db) we get the glitches spikes.

So we can not hear it continuously, but below -6db (-6 to -103 db) everything is working fine.

Thanks,

Nikhil

  • 0
    TI__Mastermind 24835 points
    Hi Nikhil,
    This is not expected. Did you enable AGL or not? Is the PVDD still stable when the volume is large? Did you measure the PWM output when the issue occurs? Is there any fault in the error status register?
  • 0 in reply to Shawn Zheng
    Prodigy 250 points

    Hi Shawn,


    we got your point, we are using 12v supply adapter so when we raise the gain after 1db. status register 0x02 got the error. and we get the tik tik sound.

    currently i made the maximum gain as 1 db and never get the error. at this point i made the 0x10 as 0x01 and tried with other modulation combination still the issue is there.

    we have the limitation to use 12v supply only, how can i achieve more gain with 12v limitation.

    Thanks,

    Nikhil

  • 0 in reply to Nikhil Sahu78
    Prodigy 250 points
    Hi Shawan,

    Just to add some of my observation.

    our board is taking current 0.150Amp and 12v in ideal case when no music is playing.

    Modulation MAXIMUM gain voltage current
    98.4% 1db 12v 0.150Amp (success 0x02 0x00)
    98.4% 3db 11.5v 1.2 Amp (error 0x02 0x02)
    93.8% 3db 11.8~12.01v 0.7~1.3A (success 0x02 0x00)
    93.8% 6db 10.8~12.01v 0.8~1.8A (success 0x02 0x00)
    93.8% 10db 10.6~12.01v 0.6~1.7A (error 0x02 0x02)

    Please suggest us on 93.8% modulation and 12v supply, how much gain we can make practically so with no error for status register.
    so that i will freeze those values in my code.

    Thanks,
    Nikhil
  • 0 in reply to Nikhil Sahu78
    TI__Mastermind 24835 points
    Hi Nikhil,
    We recommend users to set the register 0x10 with the value 0x07 to limit the max output PWM duty-cycle. Too large duty-cycle could cause OC issue for class-d device. We have a document to introduce this: www.ti.com/.../sloa259.pdf It's for close-loop class-d, but the modulation method is similar for open-loop amp.
    Did you measure the RMS voltage on the speaker when the issue occurs? How much is the input signal amplitude? 0dBFS? The output signal could be very large with 0dBFS input signal and 10dB volume. It should be clipped seriously with so large amplitude.
    The value 0x02 in the error status register means the OC or OT is triggered. Please measure the temperature on the device. make sure it's far from 150C to avoid the OT fault. How much is the saturation current on the inductor? Make sure the max output current is far below this value.
    Best regards,
    Shawn Zheng