User Guide

WLAN ASIC is powered by VBAT. VIO is required for SPI which connects WLAN ASIC to host processor. WLAN

requires 38.4 MHz reference clock which is taken from RF VCTCXO via BT/WLAN clock buffer. WLAN shares the

same antenna with BT and common RF path is shared according to the coexistence signaling between the

ASICs.

FM radio

Figure 53 FM radio

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 LDO (low drop out) voltage VAUX 2.78V.

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

RM-244

System Module and User Interface

Issue 1 COMPANY CONFIDENTIAL Page 6 –13