SI4708-C Datasheet, PDF (13/40 Pages) Silicon Laboratories – BROADCAST FM RADIO TUNER FOR PORTABLE APPLICATIONS

4. Functional Description
Si4708/09-C
Headphone
Cable
FMI
RFGND ^LNA
Si4708/09
I
ADC
DAC
LOUT
PGA
DSP
Q
ADC
DAC
ROUT
AGC
0 / 90
32.768 kHz
RCLK _TUNE
AFC
VA
VD ^REG
LOW-IF GPIO
RDS
(Si4709)
RSSI
GPO
VIO
RST
SDIO
SCLK
SEN
Figure 6. Si4708/09 FM Receiver Block Diagram
4.1. Overview
The Si4708/09 extends Silicon Laboratories Si4700 FM
tuner family, and further increases the ease and
attractiveness of adding FM radio reception to mobile
devices through small size and board area, minimum
component count, flexible programmability, and
superior, proven performance. Si4708/09 software is
backwards compatible to existing Si4700/01/02/03 FM
Tuner designs and leverages Silicon Laboratories'
highly successful and patented Si4700/01/02/03 FM
tuner. The Si4708/09 benefits from proven digital
integration and 100% CMOS process technology,
resulting in a completely integrated solution. It is the
industry's smallest footprint FM tuner IC requiring only
6.25 mm² board space and one external bypass
capacitor.
The device offers significant programmability, catering
to the subjective nature of FM listeners’ audio
preferences and variable FM broadcast environments
worldwide.
The Si4709 incorporates a digital processor for the
European Radio Data System (RDS) and the US Radio
Broadcast Data System (RBDS) including all required
symbol decoding, block synchronization, error
detection, and error correction functions.
RDS/RDBS* enables data such as station identification
and song name to be displayed to the user. The Si4709
offers a detailed RDS view and a standard view,
allowing adopters to selectively choose granularity of
RDS status, data, and block errors. Si4709 RDS
software is backwards compatible to the proven
Si4701/03, adopted by leading cell-phone and MP3
manufacturers world-wide.
The Si4708/09 is based on the superior, proven
performance of Silicon Laboratories' Si4700/01/02/03
architecture offering unmatched interference rejection
and leading sensitivity. The device uses the same
programming interface as the Si4700/01/02/03 and
supports multiple bus modes. Power management is
simplified with an integrated regulator allowing direct
connection to a 2.7 to 5.5 V battery for V_D and 2.7 to 5.5
V battery for V_A.
The Si4708/09 device’s high level of integration and
complete FM system production testing increases
quality to manufacturers, improves device yields, and
simplifies device manufacturing and final testing.
*Note: RDS/RBDS is referred to as RDS throughout the
remainder of this document.
Rev. 1.2
13