User's Manual

AC65/AC75 Hardware Interface Description

Confidential / Preliminary

AC65/AC75_hd_v00.372 Page 68 of 118 2006-08-03

3.15.3 Loudspeaker Circuit

The GSM module comprises two analog 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. Each interface

can be connected in differential and in single ended configuration. Figure 27 shows an

example of a differential loudspeaker configuration.

GSM module

AGND

EPNx

EPPx

Figure 27: Differential loudspeaker configuration

Loudspeaker impedance

EPP1/EPN1

= typ. 8Ohm

EPP2/EPN2

= typ. 32Ohm