Si4736/37/38/39-B20
BROADCAST WEATHER BAND RADIO RECEIVER
Features
NOAA weather band support (162.4– No manual alignment necessary
162.55 MHz)
Worldwide FM band support
(76–108 MHz)
Programmable reference clock
Volume control
Programmable soft mute control
Programmable de-emphasis
RDS/RBDS processor (Si4737/39
only)
Optional digital audio output (Si47/39
only)
Optional digital audio output
(Si4737/39 only)
2-wire and 3-wire control interface
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
Worldwide AM band support
(520–1710 kHz) (Si4736/37 only)
1050 Hz alert tone detection
Excellent real-world performance
Freq synthesizer with integrated VCO
Advanced AM/FM seek tuning
Automatic frequency control (AFC)
Automatic gain control (AGC)
Integrated LDO regulator
Digital FM stereo decoder
Adaptive noise suppression
AM/FM/WB digital tuning
Ordering Information:
See page 30.
Pin Assignments
Si4736/37/38/39-GM
(Top View)
Applications
Emergency radios
Table and portable radios
Stereos
Mini/micro systems
Portable media players
Boom boxes
Cellular handsets
Modules
Clock radios
Mini HiFi
20 19 18 17
NC
FMI
1
16
2
15 DOUT
14 LOUT
13 ROUT
12 GND
11 VDD
RFGND
AMI
3
4
5
GND
PAD
Description
RST
The Si4736/37/38/39 is the first digital CMOS AM/FM/WB radio receiver IC that
integrates the complete tuner function from antenna input to audio output.
6
7
8
9
10
Functional Block Diagram
Si473x
Patents pending
AMI
RDS
(Si4737/
39)
Notes:
DIGITAL
AUDIO
(Si4737/
39)
DOUT
AM
ANT
LNA
AGC
RFGND
1. To ensure proper operation and
receiver performance, follow the
guidelines in “AN383: Universal
Antenna Selection and Layout
Guidelines.” Silicon Laboratories will
evaluate schematics and layouts for
qualified customers.
DFS
GPO/DCLK
LOW-IF
FM/
WB
ANT
ADC
ADC
DAC
DAC
ROUT
LOUT
LNA
AGC
DSP
FMI
2. Place Si4736/37/38/39 as close as
possible to antenna jack and keep
the FMI and AMI traces as short as
possible.
2.7– 5.5 V
VDD
GND
CONTROL
INTERFACE
LDO
AFC
VIO
1.5–3.6 V
Rev. 1.0 4/08
Copyright © 2008 by Silicon Laboratories
Si4736/37/38/39-B20