Bluetooth Interface - Nokia RM-645 Service Manual

RM-645
System Module
Figure 43 Audio interface
The digital microphone is connected directly to RAPU.
Stereo output is provided by a separate stereo audio amplifier that is connected to EM ASIC. The output from
the stereo audio amplifier is fed to the AV connector.
The earpiece is driven directly by a built-in amplifier included in EM ASIC.
The stereo IHF speakers are driven directly by a built-in stereo amplifier included in EM ASIC.
The vibra is driven directly by a built-in amplifier included in EM ASIC.

Bluetooth interface

Bluetooth provides a fully digital link for communication between a master unit (the phone) and one or more
slave units (e.g. a wireless headset). Data and control interface for a low power RF module is provided by the
BTHFM module.
Bluetooth is physically integrated with FM radio in the BTHFM module ASIC, but from a functional point of
view they have nothing in common
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