Audio concept
Audio hardware architecture
The functional core of the audio hardware is built around two ASICs: RAPGSM engine ASIC and the mixed-
signal ASIC Retu.
Retu provides an interface for the transducers and the accessory connector. Integrated hands free stereo
speakers are driven by a D-class audio amplifier.
There are four audio transducers:
• Dynamic earpiece
• Two dynamic speakers
• Microphone module
In addition to the audio transducers, Retu also provides an output for the dynamic vibra component.
RM-123; RM-145
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