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Hi Kjetil

I recorded a noise and attached.

Hi Gary, 

Why do you want to set this high offset and what are your trying to acvhieve?
The noisefloor will be increased by 45 dB and that is what you hear on the other end. 

Best Regards, 
Kjetil 

Hi Kjetil

I use for condenser Mic input and set it as high gain.

Thanks

Gary Siu

Thanks Gary, 

You could look into adjusting the MICBIAS inside the AIC3204. 

If you in the configurator enable  custom setup under external audio device (audio interface tab) for the slave, you will see that a new panel pop's up called audio device customization. Press "reset all" and select the configuration for INACTIVE to LOW-POWER. This will set the mic bias to whatever you feel like. You should be able to set this higher than what is used today. Cross-check with the AIC3204 datasheet:

6.2.130 Page 1 / Register 51: MICBIAS Configuration Register
http://www.ti.com/lit/ds/symlink/tlv320aic3204.pdf

Hope this helps. 
Please let me know if you have any questions with regards to this. 

Best regards,
Kjetil 

Kjetil,

I try Headset kit with peaker output. We facing some problem about echo when speaker talk close the speaker output, I use condensor MIC. May I check with you whether adjusting the MICBIAS can solve this issue or not? and how to do this?

Thanks,

Hi MD Home, 

Two things you can play with, one is the input volume offset in the PurePath Wireless Configurator and the other is adjusting and playing with the MICBIAS setting. What you can do is to try to lover the microphone gain and see if this help with the issue. 

To adjust the input volume offset, please use the Volume Control panel in the cofigurator to adjust this (Fixed offset).
To adjust the MICBIAS settings you will need to enale custom setup in the audio interface panel and then alter the MICBIAS settings in the INACTIVE to LOW-POWER settings in the Audio Device Customization panel. 

In your final design you can look at implementing a echo cancellation algorithm. You will need to replace the AIC3204 with a CODEC with miniDSP capabilities (e.g the AIC3254 or similar) and have a small MCU to configure the codec/dsp as the memory for a echo cancellation algorithm exceedes what we have internal available in the CC85xx device. You can find more info on a echo cancellation algorithm here:
http://e2e.ti.com/support/data_converters/audio_converters/f/64/t/70540.aspx

Hope this helps.  
Best regards,
Kjetil 

Hi Kjetil,

Now we considering to replace AIC3204 with AIC3254. Per your suggestion, we need to have one more MCU(MCU + CC85XX) to configure echo cancellation algorithm in AIC3254?

Thanks,

We are working on  wireless MIC. In my design used CC8520 plus AIC3254 for Microphone side and CC8531 plus AIC3420 for speaker side. My question is how do we know when paring btweew Mic side and speaker successful. 

MD Home

Hi Kjetil,

Now we considering to replace AIC3204 with AIC3254. Per your suggestion, we need to have one more MCU(MCU + CC85XX) to configure echo cancellation algorithm in AIC3254?

Thanks,

Knighty Nimp

 We are working on  wireless MIC. In my design used CC8520 plus AIC3254 for Microphone side and CC8531 plus AIC3420 for speaker side. My question is how do we know when paring btweew Mic side and speaker successful.