Si4731-DEMO - Silicon Labs

Si4731-DEMO
Si4731 D EMO B OARD U SER ’ S G UIDE
1. Features
Worldwide FM band support, 76–108 MHz
Worldwide AM band support, 520–1710 kHz
Auto seek/auto scan
48 FM and 48 AM station presets
FM Radio Data Services (RDS) decoding (Pi Pty Ps RT CT AF displays)
Automatic set time/date function via RDS
Automatic Alternative Frequency (AF) switching
Automatic AM channel spacing detection
Single battery operation down to 0.9 V or three battery operation
Adjustable parameters include
Tuning spacing
Seek SNR/RSSI thresholds
Soft mute SNR/RSSI thresholds
Channel filters
Stereo and mono blend thresholds
Band limits
De-emphasis (50 or 75 µs)
AM channel spacing detection threshold
Stereo/mono indicator
Volume control with mute function
AM/FM band and signal quality indicator display
Battery voltage indicator
Calendar display
3x4 matrix keypad interface
Direct input of station frequencies
2. Overview
The Silicon Laboratories Si4731-DEMO board provides a complete portable AM/FM radio design with numerous
enhanced features that demonstrate the capabilities of the Silicon Laboratories AM/FM and MCU product families.
The Si4731-DEMO comes in a 3x3 mm 20-pin QFN package and is layout compatible with the entire Silicon Labs
Si47xx radio family of FM receivers, transmitters, and transceivers. The host MCU is a Silicon Laboratories
C8051F930 with internal oscillator and built-in DC-DC converter. A 79 x 101 dot matrix LCD provides the flexibility
to display a variety of system information including RDS. The demo board can work with either one AA battery
using the dc-dc converter of the C8051F930 MCU or three AAA batteries.
Rev. 0.1 5/08
Copyright © 2008 by Silicon Laboratories
Si4731-DEMO
Si4731-DEMO
3. Description
Figure 1 and Figure 2 shows the physical layout of the board with key components indicated.
JP1
J2
J1 U1
J15 U2 J14 LCD
S14
2
1
3
4
S15
U4
JP2
J3
Reset Key
T1
J4
JP4
JP3
KeyPad
Figure 1. Si4731-DEMO Board Top Side in Calendar Mode
U3
J5
Figure 2. Si4731-DEMO Board Bottom Side
2
Rev. 0.1
Si4731-DEMO
Power:
S14: 3 cell / 1 cell selection
S15: Power on / off
Audio connectors:
J14: Audio input (unused)
J15: Audio headphone output
Antenna selections:
J1: FM whip antenna connector
J2: FM SMA connector for FM conductive testing
J3: AM SMA connector for AM conductive testing
J4: AM air loop antenna wire connector
J5: JTAG connector
T1: Transformer for AM air loop operation (not shown)
JP1: FM antenna input selection
3
2
1-2: FM SMA (J2)
1-3: FM whip antenna (J1)
1-4: FM headphone (J15)
4
1
JP2: AM signal input selection
4
3
1
1-2: AM ferrite loop stick
1-3: AM air loop (J4)
1-4: AM SMA (J3)
2
JP3: AM antenna type selection
Open: AM ferrite loop stick antenna
Short: AM air loop antenna
JP4: FM PCB antenna selection
Short: Embedded PCB trace as FM short antenna for Si4704/05/1x/2x
Open: No PCB short antenna
Main components:
LCD: 79x101 dot matrix LCD
U1: Silicon Laboratories Si4731 AM/FM/RDS tuner
U2: Audio amplifier
U3: Silicon Laboratories C8051F930 MCU
U4: LDO
Control interface:
Reset Key: Reset button
KeyPad: 3x4 matrix buttons for human interface
Rev. 0.1
3
Si4731-DEMO
4. Operation
This section describes the operating modes of the Si4731-DEMO board. The board provides two major modes of
operation: Calendar and AM/FM radio.
4.1. Calendar Mode
Upon power on, the board automatically enters the Calendar Mode and displays the following information:
Year-month-day
Hour-minute
Day of the week
Battery voltage
The demo board display in Calendar Mode is illustrated in Figure 1.
In Calendar Mode, the SET/9 key is used to enter the setup menu. The M+/3 and M-/7 keys are used to select
different adjustable items (hour, minutes, year, day, month). The UP/4 and DOWN/8 keys are used to set the value
for each selected item.
The Calendar Mode date and time can also be set automatically with RDS Current Time (CT) information from a
broadcast radio station as described in the following section.
4.2. AM/FM Radio Mode
From Calendar Mode, the POWER button is used to enter AM/FM Radio Mode which displays the following
information:
1. Signal SNR indicator
2. Signal RSSI indicator
3. Band frequency indicator
4. Battery voltage indicator
5. Band frequency unit indicator
6. Stereo/mono indicator
7. Volume indicator
8. Band indicator
9. RDS information
The demo board display in AM/FM Radio Mode is illustrated in Figure 3 and Figure 4:
6
1
3
2
4
7
5
8
9
Figure 3. LCD Display in FM Radio Mode
4
Rev. 0.1
Si4731-DEMO
1
3
2
4
7
5
8
Figure 4. LCD Display in AM Radio Mode
4.2.1. Band Selection
In Radio Mode, the BANDS/0 key is used to switch between the AM and FM bands.
4.2.2. Time/Date Auto Set
Many radio stations broadcast RDS data including clock/time CT information. The AM/FM demo board can capture
this information to automatically set the time and date. In FM Mode, when RDS CT information is received, the CT
indicator will be displayed. The MEM/AL/1 button can be used to update the calendar date and time with the CT
information. CT information is not available on all radio stations and is normally sent only once per minute.
4.2.3. Alternative Frequency (AF) Switching
The AM/FM demo board monitors RDS for alternate frequency (AF) information. When RDS alternative frequency
information is received, the AF indicator will be displayed. If the signal quality of the currently tuned station
degrades, the radio will automatically change to one of the alternative frequency stations.
4.2.4. Tune/Seek
In Radio Mode, pressing the UP/4 or DOWN/8 button for less than 0.5 s will tune the frequency by the preset step
size. Holding the button for longer than 0.5 s but less than 3 s will perform a station seek.
4.2.5. Scan
In Radio Mode, the MSCAN/5 button is used to scan for all valid stations in the selected band and will automatically
save them into preset selections. After a scan operation, the M+/3 and M-/7 keys will cycle through the preset
station list. Scan operation can be aborted by pressing MSCAN/5 again, or by pressing the UP/4 or DOWN/8 key.
4.2.6. Parameter Settings
In Radio Mode, the SET/9 key is used to select the parameter setup menu as illustrated in Figure 5 and Figure 6.
The M+/3 or M-/7 keys will cycle through the available items in the menu. The UP/4 or DOWN/8 keys are used to
set the desired value for each item. Select “Yes” under “Factory Def” to go back to the factory default settings for all
items.
Rev. 0.1
5
Si4731-DEMO
Figure 5. LCD Display in FM Setup Menu
Figure 6. LCD Display in AM Setup Menu
4.2.7. Digit Keys
In Radio Mode, the FUNC/DIGIT key is used to switch the keypad to digital input mode. A “Dig” indicator is
displayed in this mode and all keys marked with a digit are used to input a channel frequency. A frequency is
considered valid if it lies within the band limits. If a non-valid frequency is entered, the closest band limit will be
entered and displayed.
4.2.8. Volume
The VOL+/2 or VOL–/6 keys are used to adjust the volume up or down. The board audio output will be muted when
volume is at the lowest setting.
4.2.9. AM Channel Spacing Auto Set
In AM Mode, the MEM/AL/1 key will automatically detect and set the channel spacing to either 9 or 10 kHz. The
detection criterion determines which channel spacing results in more valid stations during a band scan. The
number for the detection threshold is adjustable as described in Table 2. This operation can be aborted by pressing
the MEM/AL/1 key again.
6
Rev. 0.1
Si4731-DEMO
5. Human interface
There are 12 keys for controlling the demo board as shown in Figure 7:
MEM/AL/1
VOL+/2
M+/3
MSCAN/5
VOL-/6
M-/7
BANDS/0
FUNC/DIGIT
SET/9
UP/4
DOWN/8
POWER
Figure 7. Human Interface Keys
Each key can have a different function under each operating condition:
Calendar/Powerdown Mode: Radio function is disabled. LCD displays Calendar. Buttons can be used to set
time, etc.
Radio AM/FM Mode: Tuner IC works in powerup mode (FM or AM). Radio function is enabled. LCD displays
the radio station parameters. Buttons are used to adjust radio settings.
Digital Input Mode: Tuner IC works in powerup mode (FM or AM). Radio function is enabled. LCD displays the
radio station parameters. The buttons are used for direct digit input of station frequencies.
The functions of the buttons are summarized in Table 1:
Table 1. Key Function Description
Button/Mode
Calendar Mode
Tuner Off
Radio AM/FM Mode
Tuner On
MEM/AL/1
None
FM Mode: Used to adjust calendar using received RDS CT.
AM Mode: Used to automatically detect and set the channel spacing.
POWER
Enable radio
Disable radio function and enter calendar mode.
(Radio parameters will be saved to Flash).
SET
Enter calendar setup
menu
Enter radio setup menu.
(Parameter list in Table 2)
BANDS
None
Change between FM and AM band.
In setup menu,
change the current
calendar item by one
step.
In setup menu, change the current parameter by one step.
In radio mode, tune up or down by one step.
Fast parameter setting
Fast parameter setting.
None
Scan for all valid stations and save them to presets.
UP/
DOWN
Hold
Time <
0.5 s
0.5 s <
Hold
Time
<3s
Hold
Time
>3s
MSCAN
Perform a station seek.
Note: Combination keying is entered and exited from Radio Mode by pressing and holding the SET key then pressing the
BANDS key. A combination of the SET and the MSCAN keys will cycle through the available display items.
Rev. 0.1
7
Si4731-DEMO
Table 1. Key Function Description (Continued)
Button/Mode
Calendar Mode
Tuner Off
Radio AM/FM Mode
Tuner On
M+/ M–
In setup menu, select
next calendar item.
In setup menu, select next adjustable item.
In radio mode, tune to the next preset station.
None
Increase or decrease volume 1 step.
Vol+ /
Vol–
<3s
>3s
Quickly increase or decrease volume.
FUNC/DIGIT
None
Shift the keyboard between normal function and digital input mode.
Combination
keying
None
A: Radio IC version
B: Firmware version
C: Varactor reading
D: AGC status
Note: Combination keying is entered and exited from Radio Mode by pressing and holding the SET key then pressing the
BANDS key. A combination of the SET and the MSCAN keys will cycle through the available display items.
The FM and AM radio parameters which can be configured from setup menu are listed below in Table 2.
Table 2. Radio Configuration Parameters
FM Parameter
8
AM Parameter
Spacing: 50/100/200 kHz
Default: 100 kHz
Spacing: 1/9/10 kHz
Default: 9 kHz
RSSI Seek: 0–127 dBµV
Default: 20 dBµV
RSSI Seek: (0–63 dBµV
Default: 25 dBµV
SNR Seek: 0–127 dB
Default: 03 dB
SNR Seek: 0–63 dB
Default: 05 dB
Pre-emphasis: 50 or 75 µs
Default: 75 µs
Pre-emphasis: 00 disable, 50 µs
Default: 00
Band High Threshold: Max 108 MHz
Default:107.90 MHz
Band High Threshold: Max 1710 kHz
Default:1710 kHz
Band Low Threshold: min 76 MHz
Default: 87.50 MHz
Band Low Threshold: min 520 kHz
Default: 522 kHz
Channel Filter: 00/40/60/80/100 kHz
Default: 00 (Auto)
Channel Filter: 1/2/3/4/6 kHz
Default: 2 kHz
RClock: 0: AFC disable
32763~32773
Default: 32768
RClock: 0 AFC disable
32763~32773
Default: 32768
Smute Rate: 0–255
Default: 64
Smute Rate: 0–255
Default: 64
Smute SNR: 0–15 dB
Default: 4 dB
Smute SNR: 0–63 dB
Default: 10 dB
Smute Attenuation: (0–31 dB)
Default: 16 dB
Smute Attenuation: 0–63 dB
Default: 16 dB
Rev. 0.1
Si4731-DEMO
Table 2. Radio Configuration Parameters (Continued)
Blend Mono: 0–127 dBµV
Default: 30 dBµV
Smute Slop: 1–5
Default: 2
Blend Stereo: 0–127 dBuV
Default: 49dBuV
Set Factory Default: on/off
Default:off
AGC Override: on/off
Default: off
AM Channel Spacing Detection
Threshold: 1,2,3,4,5,6
Default = 2
AGC Index: 0–26
Default : 0
Set Factory Default: on/off
Default:off
RDS/RBDS
Default: RBDS
Rev. 0.1
9
Si4731-DEMO
6. Bill of Materials
C8051F930 MCU with 64 kB Flash program memory, 4 kB RAM, and built-in dc-dc converter
AM/FM receiver IC Si4731 with external 32768 Hz crystal oscillator support
ST7588T LCD driver IC
LM4910 Audio amplifier IC
See Table 3 for details.
Table 3. Si4731 Demo Board Bill of Materials
Item
Qty
Reference
Description
Value
1
3
C1, C16, C29
CAP,SM,0603,X7R
0.47 µF
2
2
C4, C13
CAP,SM,0603,X7R
4.7 µF
3
8
C15, C23-28, C41
CAP,SM,0603,X7R
1 µF
4
6
C10, C14, C19, C37, C39–40
CAP,SM,0603,X7R
0.1 µF
5
4
C2 ,C3, C21–22
CAP,SM,0603,X7R
22 pF
6
2
C8, C12
CAP,SM,0603,X7R
220 pF
7
2
C11, C18
CAP,SM,0603,X7R
820 pF
8
3
C5–7
CAP,SM,0603,X7R
100 pF
9
4
C17, C38, C44, C46
CAP,SM,0603,X7R
1 nF
10
8
C32–36, C54–C55 ,C43
CAP,SM,0603,X7R
NP
11
3
C30 ,C45, C53
RES,SM,0603
0R
12
1
C9
CAP,SM,1210,tantalum
100 µF/6.3 V
13
1
C31
CAP,SM,1210,tantalum
220 µF/4 V
14
4
R1–2, R3 ,R25
RES,SM,0603
0R
15
11
RES,SM,0603
10 kW
16
2
R5, R11
RES,SM,0603
12 kW
17
4
R20, R22–23, R28
RES,SM,0603
1 kW
18
2
R4,R6
RES,SM,0603
5k6
19
2
R8, R10
RES,SM,0603
6k8
20
3
R9, R16–17
RES,SM,0603
2 kW
21
2
R18–19
RES,SM,0603
100R
22
5
RES,SM,0603
NP
23
1
R12
RES,SM,0603
4k7
24
3
R13–14, R33
RES,SM,0603
100k
25
4
B1–4
FERRITE BEAD,SM,0805
2k5/100M
26
1
L1
IND,SM,0603
120 nH
27
1
L2
IND,SM,0603
270 nH
28
2
L3–4
RES,SM,0603
0R
29
1
U1
Si47xx, MLP20-3MM
Si47xx
10
R7, R27, R29–32, R34, R36–39
R15, R21 ,R24, R26 ,R35
Rev. 0.1
Si4731-DEMO
Table 3. Si4731 Demo Board Bill of Materials (Continued)
30
1
U2
LM4910,SOP8
LM4910MA
31
1
U4
REGLATOR,SOT23
XC62FP3002MR
32
1
U3
C8051F920/30-GQ,LQFP32
C8051F920/30-GQ
33
1
D1
DIODE,SM,ESD,SOT23
BAV99
34
2
D2–4
DIODE,SM,ESD,SOT23
CM1214-01ST/SO
35
1
Q1
TRANSISTOR NPN SOT23
2N3904
36
1
T1
MW AIR LOOP ANTENNA TRANSFORMER
SLMWTF01
37
1
J5
CONN,TH,2X10,HDR
38
1
J4
Wire holder
39
2
Y1–2
Crystal
32.768 kHz
40
2
J14–15
Stereo earphone jack
3.5 mm
41
2
JP3–4
CONN,TH,1X2,HDR
CONN,TH,1X2,HDR
42
2
JP1–2
CONN,TH,1X4,HDR
CONN,TH,1X4,HDR
43
4
J10–13
CONN,TH,1X5,HDR
CONN,TH,1X5,HDR
44
1
J1
BNC_VERTICAL
BNC for whip
45
2
J2-3
SMA_VERTICAL
SMA for FM/AM
46
1
S14
SLIDE SWITCH With 3 Double Pole
Double Throw Switches inside
47
1
S15
Single Pole Double Throw Switch
48
13
S1–13
Button Switch
49
1
LCD1
LCD
101*79 dots
50
1
ANT2
MW ferrite antenna
220 µH
51
1
ANT3
MW loop antenna
10–20 µH
52
1
BAT2
Battery BOX ,AAA*3 SIZE
53
1
BAT1
Battery BOX ,AA SIZE
DC–DC Power Block Circuit Part List
54
1
L5
IND,SM,1008
0.68 µH
55
1
C42
CAP,SM,0603,X7R
4.7 µF
Rev. 0.1
11
Figure 8. Si4731-DEMO Board Schematic—Radio and Audio Portions
Si4731-DEMO
7. Schematics
12
Rev. 0.1
Figure 9. Si4731-DEMO Board Schematic—MCU Portion
Si4731-DEMO
Rev. 0.1
13
Si4731-DEMO
CONTACT INFORMATION
Silicon Laboratories Inc.
400 West Cesar Chavez
Austin, TX 78701
Tel: 1+(512) 416-8500
Fax: 1+(512) 416-9669
Toll Free: 1+(877) 444-3032
Email: [email protected]
Internet: www.silabs.com
The information in this document is believed to be accurate in all respects at the time of publication but is subject to change without notice.
Silicon Laboratories assumes no responsibility for errors and omissions, and disclaims responsibility for any consequences resulting from
the use of information included herein. Additionally, Silicon Laboratories assumes no responsibility for the functioning of undescribed features
or parameters. Silicon Laboratories reserves the right to make changes without further notice. Silicon Laboratories makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does Silicon Laboratories assume any liability
arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation consequential or incidental damages. Silicon Laboratories products are not designed, intended, or authorized for use in applications intended to
support or sustain life, or for any other application in which the failure of the Silicon Laboratories product could create a situation where personal injury or death may occur. Should Buyer purchase or use Silicon Laboratories products for any such unintended or unauthorized application, Buyer shall indemnify and hold Silicon Laboratories harmless against all claims and damages.
Silicon Laboratories and Silicon Labs are trademarks of Silicon Laboratories Inc.
Other products or brandnames mentioned herein are trademarks or registered trademarks of their respective holders.
14
Rev. 0.1