User Guide

times when the Bluetooth device is in standby mode or the FM radio is switched on it is only necessary to

provide a SLEEP_CLK signal. The Bluetooth-FM ASIC is powered directly from the phone battery voltage line

(VBAT). An internal regulator is enabled when Bluetooth or FM radio is switched on.

Bluetooth audio signals are sent to and from the device using a PCM interface. The Bluetooth RF signal is

routed via a buried track to the Bluetooth antenna on the side of the PWB. An RF filter is needed between

the Bluetooth antenna and Bluetooth ASIC to prevent interference to and from the cellular phone antenna.

Phones that have both Bluetooth and WLAN use a shared antenna, as both services occupy the 2.4GHz ISM

frequency band. The co-existence signalling interface between Bluetooth and WLAN ASICs controls the RF

activity in the shared frequency band.

The audio signal from the FM radio is routed via the phone Audio ASIC to the phone headset or loudspeaker.

The external wired headset is also used as an Antenna for the FM radio. The FM radio receiver RF signal is

routed from the ASIC via a buried track to an impedance matching circuit placed near the headset connector.

The following block diagram shows how Bluetooth-FM is connected to the host engine.

Figure 52 Bluetooth & FM radio block diagram

GPS module

HW 53 supports GPSCost4.0 release. GPS module is connected to cellular engine via I2C interface and GenIO

control signals. GPS clock configuration includes dedicated GPS TCXO and reference clock from Ahneus.

RM-348; RM-349; RM-350

System Module and User Interface

Page 8 –10 COMPANY CONFIDENTIAL Issue 2