SI4707 Datasheet, PDF (1/3 Pages) Silicon Laboratories – Weather Band and SAME Data Receiver

Si4707
Weather Band and SAME Data Receiver
Description
The Si4707 is the industry's first weather band (WB) radio
receiver IC to include a specific area message encoding
(SAME) processor. Offering unmatched integration and
PCB space savings, the Si4707 requires only one external
component and less than 15 mm² of board area. Available
in a tiny 3 x 3 mm QFN package, it eliminates the need for
a front-end tuner IC, external ADC, DSP processor, RAM,
and numerous discrete components found in traditional
SAME weather band radios. The Si4707 weather band
receiver provides the space savings and low power
consumption necessary for portable devices while
delivering the high performance and design simplicity
desired for all weather alert radios.
Leveraging Silicon Laboratories' proven and patented
Si4700/01 FM tuner's digital low intermediate frequency
(low-IF) receiver architecture, the Si4707 delivers superior
RF performance combined with sophisticated digital
processing to yield best-in-class audio quality and SAME
data sensitivity.
The high integration and complete system production test
simplifies design in, increases system quality, and
improves manufacturability.
The Si4707 is a feature-rich solution including 1050 Hz
tone detection, automatic frequency control, dynamic
channel bandwidth filters, and digital tuning. In addition, the
Si4707 provides a programmable reference clock and
supports an I²C compatible 2-wire control interface, SPI,
and a Si4700/01 backwards compatible 3-wire control
interface.
The Si4707 incorporates a digital processor to provide
SAME data, advance error correction, and SAME data
quality metrics. Using this feature, the Si4707 enables
broadcast alert data such as severe thunderstorm warning
or flash flood watch to be displayed to the user.
Features
- Weather band support (162.4–162.55 MHz)
- SAME processor
- Excellent SAME sensitivity
- Byte-wise data quality metrics
- Advanced error correction
- 1050 Hz alert tone detection
- Excellent real-world performance
- Freq synthesizer with integrated VCO
- Automatic frequency control (AFC)
- Automatic gain control (AGC)
- Adaptive noise suppression
- WB digital tuning
- Low-IF direct conversion with no external ceramic 
filters
- Programmable reference clock
- Volume control
- Receive signal quality indicators (RSSI and SNR)
- 2-wire and 3-wire control interface
- Integrated LDO regulator
- 2.7 to 5.5 V supply voltage
- Firmware upgradeable
- 3 x 3 x 0.55 mm 20-pin QFN package
- Pb-free/RoHS compliant
Applications
- Emergency radios
- Table and portable radios
- Stereos
- Mini/micro systems
- Portable media players
- Boom boxes
- Cellular handsets
- Modules
- Clock radios
- Mini HiFi
Weather Band
Antenna
FMI
RFGND
32.768 kHz
RCLK
2.7–5.5 V VDD
LNA
AGC
0/90
AFC
REG
XTAL
OSC
ADC
PGA
DSP
ADC
RSSI /
SNR
SAME
CONTROL
INTERFACE
Si4707
DAC
LOUT
DAC
ROUT
GPO
GPO
Weather Band
Copyright © 2008 by Silicon Laboratories
4.2.08