damage the microphone input?

5 thoughts on “damage the microphone input?

  1. On my board today test MIC input. I test it long time ago and work good.

    I use ISD1810 audio chip for voice message. If test then (2weeks ago) the voice message was excellent. But test it today and on voice are large interference ( hum) .

    Is there any easy procedure to check if MIC input is damage or problem is different??

    If disconect all from MIC input and call to my MT then still is large interference (hum) .

    It means that the input is damaget? 

      1. This is a completely analogic electronic block and must be treated accordingly, a simple signal generator and a scope will reveal if you have correct signal at module audio inputs. Check if, software wise, you have correct channels enabled.


  2. Of course, maybe you should remember in each thread what module are you using, as a preliminary.


    There is a note that any DC voltage is not acceptable, maybe something like this happened? Not necessarily but …


    (*) WARNING : AC  means that the signals from the microphone have to be connected
    to input lines of the module through capacitors which value has to be • 100nF.          
    Not respecting this constraint, the input stages will be damaged.