Posted by Torbjrn Forsman, firstname.lastname@example.org
on March 08, 2002 at 11:58
Is any AGC function implemented in the audio paths of the Nokia 30?
My problem is as follows:
The application for the Nokia 30 will include a primitive loudspeaking emergency telephone. The type and installation of loudspeaker is already fixed (and definitely not a good choice). A very small, low cost, vandal-proof unit is used; hence a very bad sound quality and low maximum sound level results. An AGC is definitely needed in the system due to the varying signal levels from PSTN.
RE: AGC in analog audio interface of Nokia 30
Posted by Forum Nokia Developer Support,
on March 13, 2002 at 15:41
Are we talking about analog or digital audio application interface?
The signal levels and and bandwidth used at Nokia 30 application connector are specified so that it clearly fulfills GSM type approval requirements. Thus, it should be easy to connect audio applications into Nokia 30 without any additional AGC function. Anyhow, it should be noted that if the audio application does not fulfill the connector signal characteristics, additional electronics e.g. operational amplifiers may be needed.