• State Resolved
  • Locked Locked
  • Replies 5 replies
  • Subscribers 29 subscribers
  • Views 316 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:

TLV320AIC3254: TLV320AIC3254

TLV320AIC3254: DAC volume control not working

Goose Aderholdt
Prodigy 60 points
Part Number: TLV320AIC3254
Other Parts Discussed in Thread: PCM3070

Hi,

What is the correct configuration to set the DAC digital volume? I used the following I2C commands and the volume control still remained at 0dB:

/*          --------------------------------------------------------------- page 0 is selected     */
I2cWrite8bitData(0x00, 0x00);
/*          # reg[  0][ 65] = 0x20  ; LDAC volume control, 18dB Gain                               */
I2cWrite8bitData(0x41, 0x20);
/*          # reg[  0][ 66] = 0x20  ; RDAC volume control, 18dB Gain                               */
I2cWrite8bitData(0x42, 0x20);
/*          # reg[  0][ 64] = 0x00  ; Unmute LDAC/RDAC                                             */
I2cWrite8bitData(0x40, 0x00);

1667.audio_i2s_PCM3070.c

  • 0
    TI__Mastermind 39865 points

    Hi,

    Are these commands giving ACKs and can you read back that the register has been written? Also is the DRC enabled? The DRC will hijack the volume control based on it's algorithm. There are some example scripts in Chapter 4 of the Application Reference Guide that may help guide you to a working configuration.

    Best regards,
    Jeff McPherson

  • 0 in reply to Jeff McPherson
    Prodigy 60 points

    Hi Jeff,

    The commands are giving ACKs and the registers are being written. Which DRC are you referring to? The one on the miniDSP? This is my configuration:

    Thank you,

    Goose

  • 0 in reply to Goose Aderholdt
    TI__Mastermind 39865 points

    Hi Goose,

    Either DRC (miniDSP or Processing Block) will apply. In the Processing Block version you can see how the DRC in an input to the volume control of the DAC. The miniDSP DRC does the same thing in software. So depending on your DRC settings, it may be compressing the volume such that your DAC volume control in the register settings doesn't have an impact.

    However I also see you're using a PCM3070 framework. You should be using the same framework as the device you are using.

    Best regards,
    Jeff McPherson

  • 0 in reply to Jeff McPherson
    Prodigy 60 points

    Hi Jeff,

    You are correct. After removing the DRC block, the DAC volume changed to expectation. However, is there a workaround for this (such as a DRC make-up gain)? I don't want to increase the PGA gain because it raises the noise floor too high.

    Thank you,

    Goose

  • +1 in reply to Goose Aderholdt
    TI__Mastermind 39865 points

    Unfortunately there isn't a make up gain parameter in the DRC. The assumption is that the designer will use the PGA. If the PGA gain is too noisy you might need to raise the DRC threshold so that the compression isn't as aggressive. 

    Best regards,
    Jeff McPherson