TAS5805M: pop issue when the sound volume is about -60dB using TAS5805M

Hello Betty,

Typically when the device is in idle and is ON you will still see a PWM signal, can you confirm the device is not in shutdown when there is no audio. Is there a specific script they are using when the device isn't outputting audio.

Best Regards,

Luis

Hi Luis,

They wanto to reduce the power consumption, so they disable the TAS5805M when no autio input.

this may affect the pop issues? 

Hi Luis,

if the pop issue is cause by PWM stop, why we can't hear it with the large volume?

thank you

Hi  Luis,

one more question. this pop issue can be heard not only in the start but also in the whole audio playing. If it is because the PWM stop, I think it only occur at the audio start, should not be in the whole progress.

could you give comments here? thank you

Hello Betty, 

So you hear the pop while the audio plays when you change volume during the song, or you hear a pop throughout the song without any change?

Best regards,

Luis

Luis,

not change the anything during the audio plays. before the audio play, change the volume to -60dB, then play the audio, can hear the pop. then stop audio, change the volume to -10dB, can't hear the pop.

Also, customer feedback to me that they use the software to generate the sine waveform to input the TAS5805M, can't hear the pop. if they use the external audio source to input the TAS5805, they can't here it.

so, do you have some comments about what may cause the pop ?

Hello Betty,

Can you try running this script and see if you can hear the same pop

w 58 00 00 

w 58 7f 00

w 58 3a f8 

Best Regards,

Luis

Hi Luis,

I didn't find the 0x3a register in the book 00 and page 00, customer use currently version TAS5805, not the new version. 

what's the meaning of this register and why change this?

Hello Betty,

This is a configuration register that TI uses in the debug process. To undo the change of this debug register to default you can use this.

w 58 00 00

w 58 7f 00

w 58 3a f9

It should run on your device, please run the first script and see if you still see the pop at low level audio.

Also can you clarify if the change was done that the PWM is not turned off when sound is not playing. Also can you capture the PWM and Output signal for the full sequence where you hear this pop at -60dB.

Since you don't hear this pop with an different external source. Can you connect I2S source from the customer board to our TAS5805M and see if you hear the pop still.

Best Regards,

Luis

Hi Luis,

custoemr change 0x3a register to f8, can't hear the pop noise.

wha't is the use of this register? is there any other beside effect if change it to f8. thank you.

Hi Luis,

I take care of this case now instead of Betty. 

As you mentioned we need to change 0x3a register to f8 for debugging, but does this configuration change any other settings of the device？customer has this concern.

thanks!

George

Hi George,

We will follow up more internal registers setting through email.

Regards,

Matthew