Si4734/35
Broadcast AM/FM/SW/LW Radio Receiver
Description
The Si4734/35 is the industry's first fully integrated, 100%
CMOS AM/FM/SW/LW radio receiver IC. Offering
unmatched integration and PCB space savings, the
Si4734/35 requires minimal external components and less
than 20 mm
2
of board area, excluding the antenna inputs.
The Si4734/35 AM/FM/SW/LW 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/SW/LW solutions.
Leveraging Silicon Laboratories' proven and patented
Si4700/01 FM tuner's digital low intermediate frequency
(low-IF) receiver architecture, the Si4734/35 delivers
superior RF performance and interference rejection in AM,
FM, and short wave and long wave bands. The high
integration and complete system production test simplifies
design-in, increases system quality, and improves
manufacturability.
The Si4734/35 is a feature-rich solution including
advanced seek algorithms, soft mute, auto-calibrated
digital tuning, and FM stereo processing. In addition, the
Si4734/35 provides analog or digital audio output and a
programmable reference clock. The device supports I
2
C-
compatible 2-wire control interface, SPI, and a Si4700/01
backwards-compatible 3-wire control interface.
The Si4734/35 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 Si4735 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 RDS, the
Si4735 enables broadcast data such as station
identification and song name to be displayed to the user.
FM/SW
ANT
FMI
LNA
AGC
AM/LW
ANT
AMI
RFGND
LNA
AGC
2.7–5.5 V
VDD
GND
LDO
AFC
ADC
ADC
DSP
DAC
LOUT
Features
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-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
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Worldwide FM band support (64–108 MHz)
Worldwide AM band support(520–1710 kHz)
SW band support (2.3–21.85 MHz)
LW band support (153–279 KHz)
Excellent real-world performance
Freq synthesizer with integrated VCO
Automatic frequency control (AFC)
Automatic gain control (AGC)
Integrated LDO regulator
Digital FM stereo decoder
Programmable de-emphasis
Adaptive noise suppression
AM/FM/SW/LW digital tuning
No manual alignment necessary
Adjustable channel filters
EN55020 complaint
Programmable reference clock
Digital volume control
Adjustable soft mute control
RDS/RBDS processor (Si4735 only)
Optional digital audio out (Si4735 only)
2-wire and 3-wire control interface
2.7 to 5.5 V supply voltage
Wide range of ferrite loop sticks and air loop antennas
supported
-
3 x 3 x 0.55 mm 20-pin QFN package
-
Pb-free/RoHS compliant
Applications
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-
-
-
-
-
-
-
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Table and portable radios
Stereos
Mini/micro systems
Portable media players
Boomboxes
Clock radios
Modules
Entertainment systems
Cellular handsets
Si4734/35
RDS
(Si4735)
LOW-IF
DIGITAL
AUDIO
(Si4735)
DOUT
DFS
GPO/DCLK
DAC
ROUT
CONTROL
INTERFACE
VIO
1.5–3.6 V
SDIO
SEN
AM/FM Receiver
Copyright © 2008 by Silicon Laboratories
RCLK
SCLK
RST
4.1.08
Si4734/35
Broadcast AM/FM/SW/LW Radio Receiver
Selected FM Electrical Specifications
Parameter
Symbol
Input Frequency
f
RF
Sensitivity headphone matching
Sensitivity 50
Ω
matching
Input IP3
Adjacent Channel Selectivity
Alternate Channel Selectivity
Audio Frequency Reponse Low
Audio Frequency Reponse High
Audio Mono S/N
Audio THD
Audio Output Voltage
Supply Voltage*
V
D
, V
A
Interface Supply Voltage*
V
IO
Powerdown Current*
I
PD
*Note:
Applies to both FM and AM modes.
Test Condition
(S+N)/N = 26 dB
(S+N)/N = 26 dB
|f
2
– f
1
| > 1 MHz; f
0
= 2 x f
1
– f
2
±200 kHz
±400 kHz
–3 dB
–3 dB
Min
76
—
—
—
—
—
—
15
—
—
72
2.7
1.5
—
Typ
—
2.2
1.1
105
50
70
—
—
63
0.1
80
—
—
10
Max
108
—
—
—
—
—
30
—
—
—
90
5.5
3.6
—
Unit
MHz
µV EMF
µV EMF
dBµV EMF
dB
dB
Hz
kHz
dB
%
mVrms
V
V
µA
Selected AM/SW/LW Electrical Specifications
Parameter
Input Frequency
Symbol
f
RF
Test Condition
Medium wave (AM)
Short wave (SW)
Long wave (LW)
(S+N)/N = 26 dB
Min
520
2.3
153
—
—
—
54
Typ
—
—
—
25
56
0.1
60
Max
1710
21.85
279
—
—
—
66
Unit
kHz
MHz
kHz
µV EMF
dB
%
mVrms
Sensitivity
Audio S/N
Audio THD
Audio Output Voltage
Pin Assignments
GPO3/DCLK
GPO2/INT
3 x 3 x 0.55 mm, 20-pin QFN Package Information
GPO1
NC
1
20
19
18
17
16
15 DOUT
FMI 2
RFGND 3
AMI 4
RST 5
6
SEN
7
SCLK
8
SDIO
9
RCLK
10
VIO
GND
PAD
11 VDD
DFS
14 LOUT
13 ROUT
12 GND
NC
Symbol
Min
A
A1
b
c
D
D2
e
E
E2
0.50
0.00
0.18
0.27
1.60
Millimeters
Nom
0.55
0.02
0.25
0.32
3.00 BSC
1.70
0.50 BSC
3.00 BSC
1.70
Max
0.60
0.05
0.30
0.37
1.80
Symbol
Min
f
L
L1
aaa
bbb
ccc
ddd
eee
0.35
0.00
—
—
—
—
—
Millimeters
Nom
2.53 BSC
0.40
—
—
—
—
—
—
Max
0.45
0.10
0.10
0.10
0.08
0.10
0.10
1.60
1.80
AM/FM Receiver
Copyright © 2008 by Silicon Laboratories
4.1.08
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