User Guide

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.

USB

USB (Universal Serial Bus) provides a wired connectivity between a PC and peripheral devices. It is a differential

serial bus.

USB 2.0 is supported with full speed (12 Mbps).

RM-437; RM-449; RM-450

System Module and User Interface

Issue 1 COMPANY CONFIDENTIAL Page 6 –13