SI4704-D50 Datasheet, PDF (17/34 Pages) Silicon Laboratories – BROADCAST FM RADIO RECEIVER FOR CONSUMER

Si4704/05-D50
4. Functional Description
4.1. Overview
FM Antenna
FMI
RFGND
LPI
32.768 kHz _(TYP)
RCLK
2.7–5.5 V ^VA
LNA
AGC
AFC
REG
0/90
XTAL
OSC
Si4704/05
ADC
DAC
PGA
DSP
ADC
DAC
LOUT
ROUT
RSSI
RDS
(Si4705)
CONTROL
INTERFACE
GPO
DCLK
DOUT
DFS
Figure 7. Functional Block Diagram
The Si4704/05-D50 offers advanced audio processing
plus advanced RDS processing in a very small, 100%
CMOS receiver integrated circuit. The device provides
both analog and digital audio out, and a highly flexible
RDS pre-processor and 100 block RDS buffer. It is an
ideal product for handsets and portable devices seeking
to optimize both sound and data receiver performance.
For sound, the advanced audio processing is
unprecedented in portable devices. For RDS data
applications such as song-tagging, meta-data, traffic
message channel, or other open data applications, the
advanced and patented R(B)DS decoding engine offers
outstanding data synchronization and integrity. The
RDS engine includes demodulation, symbol decoding,
advanced error correction, detailed visibility to block-
error rates (BLER), advanced decoder reliability, and
synchronization status. The Si4704/05 provides
complete, decoded and error-corrected RDS groups
(100 blocks), up to 25 groups at a time. The Si4704/05
offers several modes of operation for various
applications which require more or less visibility to the
RDS status and group data.
*Note: The term “RDS” will be used to mean “RDS/RBDS”
throughout the document.
The Si4704/05 receiver draws on Silicon Laboratories’
broadcast audio expertise and patent portfolio, using a
digital low intermediate frequency (low-IF) receiver
architecture proven by hundreds of millions of Silicon
Laboratories’ broadcast audio receivers shipped
worldwide.
Silicon Labs has shipped 1/2 billion broadcast audio
receivers worldwide using this architecture. The low-IF
architecture allows the Si4704/05 to deliver superior
performance while integrating the great majority of
external components required by competing solutions.
The Si4704/05 digital integration reduces the required
external components of traditional offerings, resulting in
a solution requiring only an external bypass capacitor
and occupying board space of approximately 15 mm².
The Si4704/05 is the first FM radio receiver IC to
support embedded antenna technology, allowing the FM
antenna to be integrated into the enclosure or PCB of a
portable device. Refer to “AN383: Si47xx Antenna,
Schematic, Layout, And Design Guidelines” for antenna
design guidelines.
The Si4704/05 is feature-rich, providing highly
automated performance with default settings and
extensive programmability and flexibility for customized
system performance.
Rev. 1.0
17