SI4720 Datasheet, PDF (1/2 Pages) Silicon Laboratories – Broadcast FM Radio Transceiver for Portable Applications

Si4720/21
Broadcast FM Radio Transceiver for Portable Applications
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 mm². 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
- 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
Applications
- Cellular handsets/hands free
- MP3 players
- Portable media players
- GPS/navigation devices
- Satellite digital audio radios
- Personal computers
TX
Ant
TXO
L1
120 uH
RX
Ant
FMI
RFGND
2.7–5.5 V VDD
C1 GND
22 uF
LNA
AGC
LDO
Si472x
LIN
/DFS
RIN
/DIO
ADC
DAC
ROUT
/DIO
PGA
DSP
ADC
DAC
LOUT
/DFS
AFC
RDS
(Si4721)
GPO
CONTROL
INTERFACE
FM Transceiver
Copyright © 2007 by Silicon Laboratories
1.18.07