Audio Concept; Audio Hw Architecture; Internal Microphone - Nokia RM-57 Service Manual

RM-57/58
Nokia Customer Care System Module

Audio concept

Audio HW architecture

The functional core of the audio hardware is built around two ASICs: RAP 3G CMT engine ASIC and the mixed-
signal ASIC Retu.
Retu provides an interface for the transducers and the accessory connector. Because audio amplifiers are also
integrated into Retu, the only discrete electronics components needed for audio paths are audio filtering
components and EMC/ESD components.
There are three audio transducers:
• 8mm dynamic earpiece
• 16mm dynamic speaker
• electret microphone module
In addition to the audio transducers, Retu also provides an output for the dynamic vibra component.
TM
All galvanic audio accessories are connected to the Pop-Port accessory connector.
A Bluetooth audio module BC02 that is connected to RAP3G supports Bluetooth audio functionality.
There is a separate application ASIC, OMAP 1710, for Symbian applications.
Figure 107 Audio block diagram

Internal microphone

Internal microphone is used for HandPortable (HP) and Internal HandsFree (IHF) call modes.
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