am5728 output noise when using tlv320aic3120

Hello xixi,

This could be a system-level issue, including layout, power supply, decoupling, etc.  We will need to see the pcb layout and schematic to start with, to help determine where the issue might be.  You could also get some 'scope captures of the power supply bus, looking for noise that might be present there.

Let's first see the layout and schematic to determine how/where to proceed.

At your service,

~Leonard~ 

Hello, Xixi,

The register configuration seems to be all in order. So, this must be a hardware issue. Could you provide a schematic and layout of the audio codec portion in you application.

Additionally, I would recommend to take a look at the wiki article below:

https://e2e.ti.com/support/data_converters/audio_converters/w/design_notes/3377.common-noise-issues-in-codecs

Best regards,
Luis Fernando Rodríguez S.

HI Leonard and Luis Fernando Rodríguez S

 

             Thanks for your reply.

              The below is my schematic.

   

Just now we found that the digital ground and the analog ground is connected together.

Whether it will cause the noise. 

We also encounter a strange issue that when we set tlv320aic3120 to  SND_SOC_DAIFMT_CBM_CFM mode.

the tlv320aic3120 can not generate the I2S signal, So we have to change the  tlv320aic3120 to  SND_SOC_DAIFMT_CBS_CFS mode.

Hi, Xixi,

The analog and digital ground connections seem to be in order. The schematic shows that both grounds are separated and joined with a coil. So, this is not the root cause.

However, could you verify if the power supplies are well regulated? If the noise affects the power supplies, then all the codec will be affected too.

Best regards,
Luis Fernando Rodríguez S.

HI Luis Fernando Rodríguez S

I' m sorry the above  schematic mislead you. because the digital and the analog ground are connected together in another place.

So whether it will cause the noise

We also encounter a strange issue that when we set tlv320aic3120 to  SND_SOC_DAIFMT_CBM_CFM mode.

the tlv320aic3120 can not generate the I2S signal, So we have to change the  tlv320aic3120 to  SND_SOC_DAIFMT_CBS_CFS mode.

Thanks

regards

Hi, Xixi,

Could you tell me which BCLK and WCLK frequencies are you using? If the TLV320AIC3120 cannot generate the I2S signal, could you describe what frequencies do you have when you change to SND_SOC_DAIFMT_CBS_CFS? Additionally, what is the sampling rate that you are using?

Best regards,
Luis Fernando Rodríguez S.

HI Luis Fernando Rodríguez S.

When we use the SND_SOC_DAIFMT_CBM_CFM，The MCLK is from AM5728 CLKOUT2(D18).

we try to aplay the 44100HZ and S16_LE audio. then it reporter error and we found the WCLK and BCLK is always high level, The MCLK is 22579200.

So we changed to SND_SOC_DAIFMT_CBS_CFS，The MCLK is from AM5728 CLKOUT2(D18).

we try to aplay the 44100HZ and S16_LE audio, There will be a voice from the Speaker, But it is very noise.

We test the Bclk is 1411220HZ and the Wclk is 44102HZ.

Now we have disconnect the analog ground and the digital ground, But it still have noise.

 

Thanks 

regards

Hi, Xixi,

Could you provide details about the PLL values (P, R, J, D) and the clock dividers (MADC, NADC, MDAC, NDAC, AOSR, DOSR)? Which values are you using? The noise level is normally related with these values .

Best regards,
Luis Fernando Rodríguez S.

Dear Luis Fernando Rodríguez S.

 

Thanks for your reply

The below is my register value

Page 0 0x04 is 0x03，PLL_CLKIN = MCLK，CODEC_CLKIN = PLL_CLK

Page 0 0x05 is 0xA1，P = 2，R = 1

Page 0 0x06 is 0x08，J = 8

Page 0 0x07 is 0x00，0x08 is 0x00， D = 0

Page 0 0x0B is 0x88，NDAC = 8

Page 0 0x0C is 0x82，MDAC = 2

Page 0 0x0D is 0x00，0x0E is 0x80，DOSR = 128

Page 0 0x1B is 0x00，I2S mode,16bits， BCLK is input， WCLK is input

We also used the DAC signal-processing block PRB_P5

0x3C 0x05
0x00 0x08(select page 8)
0x01 0x04

whether it will cause the noise

best regards

xixi

Hi, xixi,

Could you try with different processing blocks and compare the results? Additionally, do you have captures about the noise issue?

Best regards,
Luis Fernando Rodríguez S.

Dear Luis Fernando Rodríguez S.

           Thanks for your reply

           We have try different DAC processing Block such as PRB_P5, PRB_P4，PRB_P16

           The noise is like before

Best regards

xixi 

Hi, Xixi,

Could you provide captures of your power supplies and the noise source?

Best regards,
Luis Fernando Rodríguez S.

Hi Luis Fernando Rodríguez S.

  I 'm not understand what is your mean by "Could you provide captures of your power supplies and the noise source?"

Thanks

Best regards

Hi, Xixi,

I would mean if you could provide some oscilloscope captures or pictures of the power supplies and the speaker noise. This will be helpful to understand the root cause.

Best regards,
Luis Fernando Rodríguez S.