> 4.2 | General Usage of the Loudspeaker Interface

> The GSM module comprises two analog differential speaker outputs: EP1 and EP2. Output EP1 is able to drive a load of 8Ohms while the output EP2 can drive a load of 32Ohms. Interface EP2 can also be connected in single ended configuration (see figures below).
> If single ended configuration is used, AGND must be separated from any other GND. In general a balanced configuration is recommended. For line output configuration the use of EP2 is recommended, because of better power supply rejection compared to EP1.

> Figure 12: Balanced loudspeaker configuration | Loudspeaker impedance EPP1/EPN1 Z L = typ. 8Ohm EPP2/EPN2 Z L = typ. 32Ohm

> Figure 13: Single ended loudspeaker configuration | Loudspeaker impedance EPP2/EPN2 Z L = typ. 32Ohm C k = 47µF