EES3 Hardware Interface Description
3.15 Audio Interfaces
71
EES3_HD_v01.100b
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2009-08-12
Confidential / Released
3.15.3
Loudspeaker Circuit
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. Inter-
face EP2 can also be connected in single ended configuration.
shows an example of
a differential loudspeaker configuration.
3.15.4
Digital Audio Interface (DAI)
The DAI can be used to connect audio devices capable of PCM (Pulse Code Modulation) or for
type approval. The following chapters describe the PCM interface functionality.
The PCM functionality allows the use of a codec like for example the MC145483. This codec
replaces the analog audio inputs and outputs during a call, if digital audio is selected by AT^SA-
IC.
The PCM interface is configurable with the AT^SAIC command (see
) and supports the fol-
lowing features:
•
Master and slave mode
•
Short frame and long frame synchronization
•
256 kHz or 512 kHz bit clock frequency
Figure 27:
Differential loudspeaker configuration
Loudspeaker impedance
EPP1/EPN1
Z
L
= typ. 8Ohm
EPP2/EPN2
Z
L
= typ. 32Ohm
