TLV320AIC3104EVM-K: Asking for how to improve mic noise on the AIC3104 EVM

SHH

Part Number: TLV320AIC3104EVM-K
Other Parts Discussed in Thread: TLV320AIC3204EVM-K

Hi Team,
Customer is using the AIC3104 on the new projects. They suffered the noise noise from micphone recording, the background noise is large.

So customer used the AIC3104 EVM and the on-board MIC to do the verification.
First, they use the GUI and select the

then, PGA gain turn to MAX and turn LEFT/RIGHT side ADC.

The background noise is obvious.
Could you provide your suggestions for how to improve the background noise?

Thanks,
SHH

over 8 years ago

0 Luis Fernando Rodriguez S. over 8 years ago

TI__Guru* 84915 points

Hi, SHH,

The background noise is strongly related to the microphone characteristics. The microphone that is used in our EVM is a single-ended microphone. This means that the background noise will be present even if the codec is configured with different gain and parameters. In order to reduce the background noise in the applications, we recommend to use differential microphones. These microphones help to improve the background noise. So, I would recommend to try connecting a differential microphone at the differential inputs to verify the changes from mic to mic.

Best regards,
Luis Fernando Rodríguez S.

0 SHH over 8 years ago in reply to Luis Fernando Rodriguez S.

TI__Mastermind 32196 points

Hi Luis,
Customer ever tried to ground the inpu by short to GND, the background noise is still large (The PGA gain is maximum 59dB).
Could you provide your comment? If using differential mic, can that sitl improve? Do you have recommended differential mic model?

Thanks,
SHH

0 SHH over 8 years ago in reply to SHH

TI__Mastermind 32196 points

Hi Luis,
Could you help for the comment?

Thanks,
SHH

0 Luis Fernando Rodriguez S. over 8 years ago in reply to SHH

TI__Guru* 84915 points

Hi, SHH,

Yes, the differential microphone could reduce the background noise. It is suggested to reduce the common noise in two inputs.

These microphones require of a different connection. The EVM uses a single-ended microphone. So, customer can connect the microphone as the following picture: