Si 4 8 4 4 - B2 0
B
ROADCAST
A
N A L O G
T
UNING
D
IGITAL
D
ISPLAY
AM/FM/SW R
ADIO
R
ECEIVER
Features
Worldwide FM band support
(64–109 MHz)
Worldwide AM band support
(504–1750 kHz)
SW band support
(2.3–28.5 MHz)
Selectable support for all AM/FM
regional bands
Enhance FM/SW band coverage
2-wire control interface
Mono/Stereo and valid station
indicator
Digital volume support
Bass/Treble support
Minimal BOM components with no
manual alignment
Excellent real-world performance
China TV channels audio carrier
reception in FM band
EN55020 compliant
Two AAA batteries with 2.0 to 3.6 V
supply voltage
Wide range of ferrite loop sticks and
air loop antenna support
24-pin SSOP package
RoHS compliant
Ordering Information:
See page 21.
Applications
Pin Assignments
Si4844-B20 (SSOP)
LNA_EN
IRQ
TUNE1
TUNE2
BAND
NC
NC
FMI
RFGND
NC
NC
AMI
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
Table and portable radios
Stereos
Mini/micro systems
Boom boxes
Clock radios
Modules for consumer electronics
Entertainment systems
Toys, lamps, and any application
needing an AM/FM/SW radio
Mini HiFi
iPhone docking
LOUT
ROUT
DBYP
VDD2
VDD1
XTALI
XTALO
SCLK
SDIO
RST
GND
GND
Description
The Si4844-B is the analog-tuned digital-display digital CMOS AM/FM/SW radio
receiver IC that integrates the complete receiver function from antenna input to audio
output. Working with the host MCU (I
2
C-compatible 2-wire control interface),
frequencies and stereo/mono information can be displayed on LCD while the analog-
tune features are kept. Si4844-B is pin-to-pin compatible with the current Si484x-A
tuner. Sharing all the advanced features of the Si484x-A, Si4844-B can support a wider
range of FM and SW bands. The Si4844-B also supports China TV channels audio
reception in FM band. The superior control algorithm integrated in the Si4844-B
provides a easy and reliable control interface while eliminating all the manual-tuned
external components used in a traditional solution.
Functional Block Diagram
Si4844-B
Si4830/34
AMI
AM
ANT
FM
ANT
RFGND
LNA
ADC
AGC
0/90
ADC
XTALI
2.0~3.6V VDD1/2
REG
AFC
CONTROL INTERFACE
XTAL
OSC
SCLK
BAND
TUNE1/2
ADC
DSP
DAC
ROUT
DAC
LOUT
This product, its features, and/or its
architecture is covered by one or more of
the following patents, as well as other
patents, pending and issued, both
foreign and domestic: 7,127,217;
7,272,373;
7,272,375;
7,321,324;
7,355,476;
7,426,376;
7,471,940;
7,339,503; 7,339,504.
FMI
Rev. 1.0 5/13
Copyright © 2013 by Silicon Laboratories
SDIO
RST
IRQ
Si4844-B20
Si4844-B20
T
ABLE O F
C
ONTENTS
Section
Page
1. Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
2. Typical Application Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3. Bill of Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4. Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.2. FM Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
4.3. AM Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
4.4. SW Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.5. Frequency Tuning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.6. Band Select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
4.7. Bass and Treble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
4.8. Volume Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.9. Stereo Audio Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.10. Stereo DAC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.11. Soft Mute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.12. Reference Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.13. Reset, Powerup, and Powerdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.14. Memorizing Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.15. Programming with Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5. Commands and Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
6. Pin Description: Si4844-B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
7. Ordering Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
8. Package Outline: Si4844-B20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
9. PCB Land Pattern: Si4844-B20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
10. Top Marking: Si4844-B20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
11. Additional Reference Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Document Change List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Contact Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Rev. 1.0
3
Si4844-B20
1. Electrical Specifications
Table 1. Recommended Operating Conditions
1,2
Parameter
Supply Voltage
3
Power Supply Powerup Rise Time
Symbol
V
DD
V
DDRISE
Test Condition
Min
2
10
Typ
—
—
Max
3.6
—
Unit
V
µs
Notes:
1.
Typical values in the data sheet apply at V
DD
= 3.3 V and 25 °C unless otherwise stated.
2.
All minimum and maximum specifications in the data sheet apply across the recommended operating conditions for
minimum V
DD
= 2.7 V.
3.
Operation at minimum V
DD
is guaranteed by characterization when V
DD
voltage is ramped down to 2.0 V. Part
initialization may become unresponsive below 2.3 V.
Table 2. DC Characteristics
(V
DD
= 2.7 to 3.6 V, TA = –15 to 85 °C)
Parameter
FM Mode
Supply Current
1
Supply Current
2
AM/SW Mode
Supply Current
1
Supplies and Interface
V
DD
Powerdown
Current
Symbol
Test Condition
Min
Typ
Max
Unit
I
FM
I
FM
I
AM
I
DDPD
Low SNR level
—
—
21.0
21.5
—
—
mA
mA
—
20.0
—
mA
—
10
—
µA
Notes:
1.
Specifications are guaranteed by characterization.
2.
LNA is automatically switched to higher current mode for optimum sensitivity in weak signal conditions.
4
Rev. 1.0
Si4844-B20
Table 3. Reset Timing Characteristics
(V
DD
= 2.7 to 3.6 V, TA = –15 to 85 °C)
Parameter
RSTB Pulse Width
2-wire bus idle time after RSTB rises
2-wire bus idle time before RSTB rises, and VDD valid
time before RSTB rises
RSTB low time before VDD becomes invalid
Notes:
Symbol
t
PRST
t
SDIO
t
SRST
t
RRST
Min
100
100
100
0
Typ
—
—
—
—
Max
—
—
—
—
Unit
µs
µs
µs
µs
1.
RSTB must be held low for at least 100 µs after the voltage supply has been ramped up.
2.
RSTB needs to be asserted (pulled low) prior to the supply voltage being ramped down.
t
SRST
VDD
t
SDIO
t
PRST
t
SDIO
t
RRST
RSTB
SCLK
POWER_UP
Normal
Operation
POWER_UP
Normal
Operation
SDIO
Figure 1. Reset Timing
Rev. 1.0
5
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