• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 30 subscribers
  • Views 690 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.

How to configure TAS5727 DRC?

Andrew Kimpel3
Prodigy 50 points
Other Parts Discussed in Thread: TAS5727EVM, TAS5727

Hello TI,

I am currently trying to configure and enable the DRC in the TAS5727M in order to implement a peak limiter to protect for transducer over-excursion. Referring to the app note "TAS57xx Dynamic Range Control" (sloa148.pdf), it appears that the DRC in the TAS5727M is more "limited" than what the app note describes, i.e. does not allow for setting of the compression ratio K and offset O. Many of the registers indicated in the sloa148 app note show up as 'reserved' in the TAS5727M I2C memory map (0x3A, 0x3D, 0x41-0x42, 0x44-0x45). It also appears that the I2C register addresses are incorrect in sloa148, when compared to the TAS5727M datasheet. Also, when connected to my TAS5727EVM, the DRC configuration pop-up window in the TAS57XX GDE is different than what is shown in the app note. Since it appears the compression ratio K and offset O are not adjustable, what are the default settings? I am assuming K = infinite and O = 0dB, but can you confirm this?

Any suggestions you have on how to configure the TAS5727M DRC would be most helpful, as well as information you may have on the differences in DRC operation between this device and the other devices in the TAS57xx family.

  • 0
    TI__Guru 57800 points

    Hi Andrew,

    The TAS5727 has actually a different type of DRC that is more advanced and easier to configure, called AGL. The AGL requires only the adjustment for the threshold, keeping a  fixed slope and offset (technically, K= 0, O=0).


    AGL tuning depends heavily on the end-system performance desired by the customer, so you may want to use the GUI for this. 

    Best Regards,

      -Diego Meléndez López
       Audio Applications Engineer

  • 0 in reply to Diego Melendez
    Prodigy 50 points
    Thank you, that's helpful. Do you have any advice / guidelines for setting the softening ("alpha filter") parameters {alpha, omega}? It's not clear to me if the softening filter adjusts the compression "knee" or is this filter part of the RMS estimation calculation? Is there a suggesting tuning method? I am using the GUI to set the DRC, but it's not intuitive to me what this softening filter GUI slider affects.

    Our application is a subwoofer product, and we are using the TAS5727M in PBTL (mono) mode with single-band DRC. Prior to the DRC, we are incorporating a steep 8th-order LPF at 125Khz, so all of the energy into the DRC is low-frequency (bass).

    best,
    Andrew
  • 0 in reply to Andrew Kimpel3
    TI__Guru 57800 points

    Hi Andrew,

    Softening filter parameters are part of the RMS estimator, you can follow the guidelines of SLOA148 to configure them, however, we usually recommend to leave them as default for most applications. The GUI of the TAS5727 can be used on your end system to verify the limiter level you want to achieve. 

    Regards,

      -Diego Meléndez López
       Audio Applications Engineer