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Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
3. TECHNICAL BRIEF
LGE Internal Use Only
3.16. FM Radio
The BCM2048 includes a completely integrated FM radio receiver with RDS/RBDS covering all FM bands from
76 MHz to 108 MHz. The receiver is controlled through commands on the I2C-compatible bus or the HCI. FM
audio is available as stereo analog output or in digital form through I2S or PCM. The FM subsystem can
operate independently or in tandem with the Bluetooth subsy- stem and can be powered up or down
separately.
SENSITIVITY
The internal LNA has a noise value of 6 dB, which helps achieve excellent sensitivity of –107dBm, or 1
μ
V in
50
Ω
.
DIGITAL FM OUTPUT
The FM radio audio is available digitally through the shared PCM and I2S pins and the sampling rate is
nominally at 48 kHz. The PCM interface runs off either the FM or the Bluetooth clock. The BCM2048 supports
three-wire I2S audio interface in either master or slave configuration. The master or slave configuration is
selected via HCI commands. In addition, multiple sampling rates are supported, derived from either the FM or
Bluetooth clocks.
OTHER FEATURES
• Single-ended or differential FM RF input
• Auto search and tuning
• Signal dependent mono/stereo blend
• Soft mute
• Programmable de-emphasis
• Digital-level indicator (RSSI, IF Frequency)
• Low current consumption
I2C-COMPATIBLE BUS
The BCM2048 implements a slave I2C-compatible bus interface for control of the FM subsystem. The interface
supports a clock rate up to 400 kHz. The I2C-compatible slave address is programm- able using the UART HCI
interface and requires a configuration download. The interface supports seven-bit addressing mode. This
interface may require external pull-ups.
RDS/RBDS
The BCM2048 integrates a RDS/RBDS demodulator and decoder with programmable filtering and buffering
functions. The RDS/RBDS data can be read out through either the HCI or I2C- compatible interfaces. In
addition, the RDS/RBDS functionality supports the following:
• Block decoding, error correction and synchronization
• Storage capability up to 126 blocks of RDS data
• Full or partial block B match detect and interrupt to host
• Audio pause detection with programmable parameters
• Program Identification (PI) code detection and interrupt to host
• Automatic frequency jump
• Block E filtering