SI4730-D50 Datasheet, PDF (18/34 Pages) Silicon Laboratories – BROADCAST AM/FM RADIO RECEIVER

Si4730/31-D50
4. Functional Description
4.1. Overview
AMI
AM
ANT
RFGND
FM
ANT
FMI
2.7– 5.5 V _VA
GND
LNA
AGC
LNA
AGC
LDO
Si473x
RDS
(Si4731)
LOW-IF
DIGITAL
AUDIO
DOUT
DFS
GPO/DCLK
ADC
DAC
DSP
ADC
DAC
ROUT
LOUT
AFC
CONTROL
INTERFACE
VD
1.62–3.6 V
Figure 7. Functional Block Diagram
The Si4730/31-D50 is Silicon Labs’ fourth generation
fully integrated, 100% CMOS AM/FM radio receiver IC.
Offering unmatched integration and PCB space
savings, the Si4730/31 requires only two external
components and less than 15 mm² of board area,
excluding the antenna inputs. The Si4730/31 AM/FM
radio provides the space savings and low power
consumption necessary for portable devices while
delivering the high performance and design simplicity
desired for all AM/FM solutions.
Leveraging Silicon Laboratories' proven and patented
Si4700/01 FM tuner's digital low intermediate frequency
(low-IF) receiver architecture, the Si4730/31 delivers
superior RF performance and interference rejection in
both AM and FM bands. The high integration and
complete system production test simplifies design-in,
increases system quality, and improves
manufacturability.
The Si4730/31 is a feature-rich solution that includes
advanced seek algorithms, soft mute, auto-calibrated
digital tuning, FM stereo processing, and advanced
audio processing.
In addition, the Si4730/31 provides analog and digital
audio outputs and a programmable reference clock. The
device supports I²C-compatible 2-wire control interface,
SPI, and a Si4700/01 backwards-compatible 3-wire
control interface.
The Si4730/31 utilizes digital processing to achieve high
fidelity, optimal performance, and design flexibility. The
chip provides excellent pilot rejection, selectivity, and
unmatched audio performance, and offers both the
manufacturer and the end-user extensive
programmability and flexibility in the listening
experience.
The Si4731 incorporates a digital processor for the
European Radio Data System (RDS) and the North
American Radio Broadcast Data System (RBDS)
including all required symbol decoding, block
synchronization, error detection, and error correction
functions. Using this feature, the Si4731 enables
broadcast data such as station identification and song
name to be displayed to the user.
4.2. Operating Modes
The Si4730/31 operates in either an FM receive or an
AM receive mode. In FM mode, radio signals are
received on FMI and processed by the FM front-end
circuitry. In AM mode, radio signals are received on AMI
and processed by the AM front-end circuitry. In addition
to the receiver mode, there is an audio output mode to
choose between an analog and/or digital audio output.
In the analog audio output mode, ROUT and LOUT are
used for the audio output pins. In the digital audio mode,
DOUT, DFS, and DCLK pins are used. Concurrent
analog/digital audio output mode is also available
requiring all five pins.
18
Rev. 1.0