User Guide

Figure 96 Bluetooth interface

The Bluetooth has a separate built in antenna and is powered by VBAT and the regulated voltage VIO. For

audio applications the Bluetooth has a PCM data bus. In addition a UART (universal asynchronous receiver/

transmitter) is used for data communication and controls.

FM radio

The FM radio is physically integrated with the Bluetooth into one single module. From a functional point of

view they, however, have nothing in common.

The FM radio is an integrated circuit, controlled by MCU software through a serial bus interface. The wires of

the headset are used as elements of the antenna, and no other antenna is needed for FM radio reception.

The FM radio is provided with VAUX (2V8).

The radio has an automatic band search function, which can search for a strong station.

RM-135

System Module and User Interface Nokia Customer Care

Issue 1 COMPANY CONFIDENTIAL Page 7 –15