I'd like to connect sim300cz's mic & speaker interface to a codec. the codec has mic and speaker pins. So I connect these two pins of both modules, i.e, mic to speaker and vice versa.
But, I'm not sure about the voltage level compatibility between these pins.
When I read sim300cz's datasheet, I get little confused. I read the Audio interface section, reference electronic characteristics.
It says that:
MIC input: working voltage:min 1.2v, max 2v
Normal output SPK1: ref level: 1.0954v, -6.02 dBm
can anyone explain these data, what is the meaning of working voltage and ref level in above?
Thanks.