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RE: TAS2563: Multi-Stage Volume Ramp During Playback After Device Turn-On

Other Parts Discussed in Thread: OPA1652, ADS1271, THS4521

Hey Ivan,

If I integrate over the entire frequency spectrum for the normalized displacement, I get approx. 9.5 mm/V...this seems quite high relative to the maximum value allowed (10 mm). What is the largest speaker that this smart amplifier can accommodate? Our speaker is quite small...so for a speaker ever marginally larger, the integrated Xmax would be higher than the maximum Xmax allowed. A few other values i've calculated:

  • 200 Hz - 2 kHz: 5.4 mm/V
  • 200 Hz - 1600 Hz: 5.3 mm/V
  • 200 Hz - 1250 Hz: 5.0 mm/V
  • 200 Hz - 1 kHz: 4.7 mm/V

Is there a rule-of-thumb for what range to integrate over? 

  • Oren,

    • 9dB helps to bring up the low amplitude content on the audio track, the basic idea is to cause a higher excursion and verify excursion protection keeps the speaker within the limit
    • Attached is the audio file, it's a combination of different sounds and at the end a 3kHz tone to heat up the speaker.

    Best regards,
    -Ivan Salazar
    Applications Engineer

  • Hi Ivan,

    When using the provided audio file we were able to measure excursion profiles similar to the ones in your report.  The power profile is well-behaved through most of the test except when the FS 3 kHz tone is applied.  Even though the measured excursion is small the amplifier's power draw averages ~2 W.  The screenshot shows a current probe measurement at EVB VBAT1 as the 3 kHz segment begins:

    Can you please advise how to limit the power draw in this case?  The limiter settings and the temperature rise apparently don't catch it.

    Thanks, O.R.

  • Hi Oren,

    ~3kHz is the impedance minimum after resonance frequency, perhaps adding a notch filter around this frequency would help to keep current low. Please consider this test tone was used specifically to heat up the speaker.

    Is there a specific current limit you're looking for? Setting up the boost controller on Device Control panel would be an alternative.

    Best regards,
    -Ivan Salazar
    Applications Engineer

  • Hi Ivan,

    1 A transient peaks are allowed with program material.  The power budget is 314 mW average per amplifier.

    Thanks, O.R.   

  • Hi Oren,

    I'll share some fine tuning to reduce the current peaks, you can evaluate and do changes if needed.
    Is it OK if I share a link with a password for a shared folder so we can update through it instead of sending new files each time? If it's OK I'll send the details through our FAE.

    Best regards,
    -Ivan Salazar
    Applications Engineer

  • Re: Limiter Not Working on Sine Waves

    Continued in this tread:

    e2e.ti.com/.../tas2563-limiter-not-working-on-sine-waves

  • Hi Ivan, yes, please send details through the FAE.  Thanks, O.R.

  • Oren,

    I'll follow up on the new thread and close this one.

    Best regards,
    -Ivan Salazar
    Applications Engineer

  • Hi Ivan, please keep this tread open for the original topic.  Thanks, O.R.

  • Oren,

    I thought you were splitting due to high reply count on this one. This thread will remain open as long as there is no long time (months) without replies. Please follow up on each thread as needed.

    Best regards,
    -Ivan Salazar
    Applications Engineer