Si4720/21
Description
The Si4720/21 is the first single chip FM radio transceiver.
The proven and patented digital architecture of the Si4720/
21 combines the functionality of the Si470x FM radio
receiver with the Si471x FM transmitter, offering full FM
receive and transmit capabilities in a single, ultra-small
3x3x0.55 mm QFN package. The device leverages Silicon
Lab's highly successful and proven FM technology, and
offers unmatched integration and performance allowing FM
receive and transmit to be added to any portable device by
using a single chip. As with the Si470x and Si471x
products, the Si4720/21 offers industry leading size,
performance, low power consumption, and ease of use.
The Si4720/21's digital integration reduces the required
external components of traditional offerings, resulting in a
solution requiring only an external inductor and bypass
capacitor, and a PCB space of approximately 15 mm
2
. The
Si4720/21 is layout compatible with Silicon Laboratories'
Si470x FM radio receivers, Si473x AM/FM radio receivers,
and the Si471x FM radio transmitter solutions, allowing a
single PCB layout to accommodate a variety of music
features. High yield manufacturability, unmatched
performance,
easy
design-in,
and
software
programmability are key advantages of the Si4720/21.
The Si4721 is the industry's first single-chip integrated FM
radio transceiver including both receive and transmit
support for the European Radio Data System (RDS) and
the U.S. Radio Broadcast Data System (RBDS). RDS
allows digital information sent from the broadcaster to be
displayed, such as station ID, song name and music
category. In Europe, alternate frequency (AF) information is
also provided to automatically change stations in areas
where broadcasters use multiple frequencies. In transmit
mode, digital information such as artist name, song title,
music category, and branded messaging can be
transmitted and displayed on any RDS/RBDS receiver.
Users are responsible to adjust their system's radiated
power levels to comply with local regulations on RF
transmission (FCC, ETSI, ARIB, etc.).
Features
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Integrated FM antenna support
Excellent real-world performance
Only two external components required
Worldwide FM band support (76 to 108 MHz)
RDS/RBDS processor (Si4721)
Frequency synthesizer with integrated VCO
Adjustable seek parameters
Adjustable mono/stereo blend
Adjustable soft mute
Programmable transmit output voltage control
Audio dynamic range control
Advanced modulation control
Analog/digital audio interface
Programmable reference clock input
Programmable pre/de-emphasis (50/75 µs)
2-wire and 3-wire control interface
Integrated LDO regulator
2.7 to 5.5 V supply voltage
3x3x0.55 mm 20-pin Pb-free QFN package
Cellular handsets/hands free
MP3 players
Portable media players
GPS/navigation devices
Satellite digital audio radios
Personal computers
Applications
Si472x
TX
Ant
L1
120 uH
TXO
LIN
/DFS
RIN
/DIO
RX
Ant
FMI
RFGND
ADC
PGA
MUX
LNA
AGC
DSP
ADC
DAC
ROUT
/DIO
LOUT
/DFS
DAC
2.7–5.5 V
VDD
C1
22 uF
GND
LDO
AFC
RDS
(Si4721)
GPO
CONTROL
INTERFACE
GPO2
SCLK
RCLK
GPO1
SEN
RST
FM Transceiver
Copyright © 2007 by Silicon Laboratories
GPO3/DCLK
SDIO
VIO
1.18.07
SILABS [ SILICON LABORATORIES ]
