Sim908 mic noise

[mastero]

Hello all

I am using Sim908 for my project but am getting a lot of noise on the MIC when in an active call.

anyidea ?

its a electret mic and using the standard design in the data sheet

thanx

mastero

 

[ronv]

You might try shielded twisted pair cable.

 

[audioguru]

You forgot to describe the "noise".
Is it low frequency mains hum?
Is it high frequency hiss from the un-named opamp?
Is it background noise?

We don't know what is "the standard design in the datasheet." Please post it.

 

[mastero]

The noise is RFI

 

[unclejed613]

is this being used with a cell phone? if so you need to be using shielded twisted pair. how is this powered? it looks like the power goes through the "differential" line and the audio is on a single wire. the audio wire needs to be shielded as well.