TLV320AIC3104: Audible modulated noise

Kuramochi Tadahiko

Guru 28715 points

Part Number: TLV320AIC3104

Hi,

My customer is evaluating the TLV320AIC3104 on their system.

Modulated audible noise can be heard as attached when small white noise is inputted.

The frequency(pitch) of noise depends on the volume of white noise.

Is there any workaround to avoid this audible noise?

Please let me know if you have any questions.

Best Regards,

Kuramochi

over 4 years ago

0 Aaron Estrada over 4 years ago

TI__Mastermind 22950 points

Hi Kuramochi-san,

Can you please provide some more information regarding the configuration of the CODEC such as:

- Please provide an I2C register dump of the device.

- Clock information such as WCLK, BCLK and/or MCLK frequencies

- This looks to be on the recording path, is this correct?

- Can you please provide a schematic?

Regards,

Aaron Estrada

0 Kuramochi Tadahiko over 4 years ago in reply to Aaron Estrada

Guru 28715 points

Aaron-san,

Thank you for your reply.

I send a friendship request to provide the above information.

Could you accept it?

Best Regards,

Kuramochi

0 Kuramochi Tadahiko over 4 years ago in reply to Kuramochi Tadahiko

Guru 28715 points

Hi Aaron-san,

What does "recording path" mean?

Best Regards,

Kuramochi

0 Aaron Estrada over 4 years ago in reply to Kuramochi Tadahiko

TI__Mastermind 22950 points

Hi Kuramochi-san,

I accepted your friend request.

Record path is referring to analog input to the ADC and digital output.

Regards,

Aaron Estrada

0 Kuramochi Tadahiko over 4 years ago in reply to Aaron Estrada

Guru 28715 points

Hi Aaron-san,

Thank you for your support.

I send some files a while ago.

Please refer them.

>- This looks to be on the recording path, is this correct?

Yes, right.

Best Regards,

Kuramochi

0 Kuramochi Tadahiko over 4 years ago in reply to Kuramochi Tadahiko

Guru 28715 points

Hi Aaron-san,

CLK frequency is as below;

WCLK:48kHz, BCLK:3.072MHz, MCLK:12.288MHz,

Best Regards,

Kuramochi

0 Kuramochi Tadahiko over 4 years ago in reply to Kuramochi Tadahiko

Guru 28715 points

Hi Aaron-san,

How is this situation?

Best Regards,

Kuramochi

0 Aaron Estrada over 4 years ago in reply to Kuramochi Tadahiko

TI__Mastermind 22950 points

Hello Kuramochi-san,

Extreme apologies on the delay here.

I looked at the register configuration and the devices looks to be configured appropriately. Moving forward, I have a few questions:

- How are you feeding this white noise to the CODEC?

- Is it possible to send a file of the input so I can test this out on an eval board?

- What happens if a sine wave is sent to the device? Can the customer perform a recording of a sine wave?

Regards,

Aaron Estrada

0 Kuramochi Tadahiko over 4 years ago in reply to Aaron Estrada

Guru 28715 points

Hi Aaron-san,

- How are you feeding this white noise to the CODEC?

Actually, they do not input signals.

ADC and DAC are connected via only DSP to gain volume.

- Is it possible to send a file of the input so I can test this out on an eval board?

As above, they do not input signals.

- What happens if a sine wave is sent to the device? Can the customer perform a recording of a sine wave?

They're confirming.

I have two additional pieces of information.

・When HPF is set to fc=20Hz, this noise is eliminated.

・The following files are a spectrum of this noise.

3326.3104 noise caused by white noise at 1.1kHz.xlsx

Best Regards,

Kuraqmochi

0 Aaron Estrada over 4 years ago in reply to Kuramochi Tadahiko

TI__Mastermind 22950 points

Hi Kuramochi-san,

It is a bit difficult to say how the CODEC will behave with a white noise input as all device specs are spec'd with a 1kHz sine wave input. Is there a reason the customer was using white noise as a test?

Regards,

Aaron Estrada

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TLV320AIC3104: Audible modulated noise