TLV320AIC3268: Headphone Volume Ramp

Phil Hale

Part Number: TLV320AIC3268

Guys,

I am using a pot to adjust to adjust the volume control on the headphone.

The headphone output volume control varies from -6dB to +14dB (B0_P1_R31 and B0_P1_R32).

Is there a nice way to ramp the audio levels from the previous setting to the new setting over a period of time? Right now, I am getting a very audible stepping when the volume changes.

Thank you in advance.

Phil

over 3 years ago

0 Phil Hale over 3 years ago

Intellectual 630 points

I have a second, related question. The datasheet, SLAS953A states "Do not change after HP amp power-up". As stated above, I need the headphone to have volume control capabilities. Is there a different method I should be using?

0 Sanjay Dixit over 3 years ago in reply to Phil Hale

TI__Mastermind 23030 points

Shall reply by 21/8

0 Sanjay Dixit over 3 years ago in reply to Sanjay Dixit

TI__Mastermind 23030 points

Have you Tried Digital Volume Control of the DAC?

Book 0 / Page 0 / Register 65: Primary DAC Left Volume Control Setting - 0x00 / 0x00 / 0x41 (B0_P0_R65)

There is a soft stepping feature enabled by B0_P0_R63

0 Phil Hale over 3 years ago in reply to Sanjay Dixit

Intellectual 630 points

I have an I2S output that is being sent to a host computer. I am using the headphone to listen to what is being sent to the host computer. I cannot change the amplitude of the host computer audio without causing more issues. Incidentally, I do use the DAC volume control setting as my "master output" but I need to control the headphone audio levels using a knob/potentiometer kind of solution.

0 Sanjay Dixit over 3 years ago in reply to Phil Hale

TI__Mastermind 23030 points

Did you try to use the DAC Volume control for trying to adjust headphone volume? This one does have soft stepping on it.

0 Phil Hale over 3 years ago in reply to Sanjay Dixit

Intellectual 630 points

Yes, it works. However, this solution has a negative consequence of increasing the gain on the I2S and LOL/LOR outputs. I2S is the most critical to maintain the consistent gain level at all times. And, the DSP is doing DRC dynamic gain adjustments at the same time.

+1 Sanjay Dixit over 3 years ago in reply to Phil Hale

TI__Mastermind 23030 points

The Headphone registers on Page1,R31,R32 are not really meant to be changed once it is powered up.

Perhaps with page 1, Reg27 you could try powering down the Headphone, Loading a new Value in R31,R32 and then repowering up with Reg 27.

0 Phil Hale over 3 years ago in reply to Sanjay Dixit

Intellectual 630 points

That is unfortunate but I could not find another method either.

Thank you for your analysis. Most appreciated, Sanjay.

Phil

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TLV320AIC3268: Headphone Volume Ramp