What impedence setting should I choose for my SPA3102 FXO port?

If you can match the impedance setting expected by your country's PSTN, you will have much better results in detecting the proper state of your PSTN line as well as have better audio quality.

The following settings apply to various countries:

    * 600 ohms (US/Canada)

    * 900 ohms (US/Canada)

    * 220+820//115nF (Germany)

    * 200+680//100nF (China)

    * 370+620//310nF (UK)

    * 180+910//150nF (France)

    * 270+750//150nF (Sweden)

    * 120+820//110nF (Norway)

    * 150+830//72nF (Belgium)

    * 400+500//330nF (Denmark)