SI4720-B20 Datasheet, PDF (1/48 Pages) Silicon Laboratories – BROADCAST FM RADIO TRANSCEIVER FOR PORTABLE APPLICATIONS

Si4720/21-B20
BROADCAST FM RADIO TRANSCEIVER FOR PORTABLE APPLICATIONS
Features
 Full FM RX and TX in 3 x 3 QFN  Adjustable seek parameters
 Worldwide FM RX band support _{ Adjustable mono/stereo blend}
 Compliant with worldwide FM TX _{ Adjustable soft mute}
regulations
 Excellent real-world performance ^{ Advanced modulation control}
 Supports integrated TX/RX
 Audio dynamic range control
antenna
 Audio silence detector
 Programmable transmit output _{ Programmable reference clock}
voltage
input
 Frequency synthesizer with
integrated VCO
 Integrated LDO regulator
 Minimal BOM (15 mm²)
 Digital audio output
(Si4721 only)
 Digital audio input
 2-wire and 3-wire control
interface
 2.7 to 5.5 V supply voltage
 3 x 3 x 0.55 mm 20-pin Pb-free
QFN package
 RDS/RDBS encoder/decoder
(Si4721 only)
Applications
 Cellular handsets/hands-free
 MP3 players
 Portable media players
Description
 Wireless speakers/microphone
 Satellite digital audio radios
 Personal computers/notebooks
The Si4720/21 integrates the complete tuner and transmit functions for
FM broadcast reception and standards-compliant, unlicensed FM
broadcast stereo transmission. Users must comply with local radio
frequency (RF) transmission regulations.
Functional Block Diagram
Tx/Rx Ant
TXO
L1
120 nH
Si4720/21
LIN/DFS
RIN/DOUT
Rx Ant*
FMI
LNA
ADC
DAC
ROUT/DIN
PGA
DSP
RFGND
AGC
ADC
DAC
LOUT/DFS
2.7–5.5 V VDD
C1 GND
22 uF
LDO
AFC
GPO
CONTROL
INTERFACE
Ordering Information:
See page 42.
Pin Assignments
Si4720/21
(Top View)
NC 1 ^{20 19 18 17} 16
FMI 2
15 RIN/DOUT
RFGND 3
TXO 4
GND
PAD
14 LOUT/DFS
13 ROUT/DIN
RST 5
12 GND
6 _{7 8 9 10} 11 VDD
Patents pending
Notes:
1. To ensure proper operation and FM
transceiver performance, follow the
guidelines in “AN383: 3 mm x 3 mm
QFN Universal Layout Guide.”
Silicon Laboratories will evaluate
schematics and layouts for qualified
customers.
2. Place the Si4720/21 as close as
possible to the antenna jack, and
keep the FMI trace as short as
possible.
*Note: Dedicated Rx antenna is optional
Rev. 1.0 2/08
Copyright © 2008 by Silicon Laboratories
.
Si4720/21-B20