SI4708-C Datasheet, PDF (12/40 Pages) Silicon Laboratories – BROADCAST FM RADIO TUNER FOR PORTABLE APPLICATIONS

Si4708/09-C
2. Typical Application Schematic
R1
GPO
LOUT
FMI
RFGND
1
2
3
4
NC
FMIP
RFGND
RST
ROUT ¹²
GND ¹¹
VD ¹⁰
RCLK ⁹
ROUT
VBATTERY
2.7 to 5.5 V
C1
RST
SEN
RCLK
SCLK
SDIO
VIO
1.62 to 3.6 V
Notes:
1. Place C1 close to V_D pin.
2. All grounds connect directly to GND plane on PCB.
3. Pins 1 and 16 are no connects, leave floating.
4. Important Note: FM Receiver performance is subject to adherence to antenna design guidelines in “AN350: Si4708/09
Antenna, Schematic, Layout, and Design Guidelines.” Failure to use these guidelines may negatively affect the
performance of the Si4708/09, particularly in weak signal and noisy environments. Silicon Laboratories will evaluate
schematics and layouts for qualified customers.
5. Pin 2 connects to the antenna interface, refer to “AN350: Si4708/09 Antenna, Schematic, Layout, and Design
Guidelines” and "AN383: Si47xx Antenna, Schematic, Layout, and Design Guidelines."
6. RFGND should be locally isolated from GND, refer to “AN350: Si4708/09 Antenna, Schematic, Layout, and Design
Guidelines.”
7. Place Si4708/09 as close as possible to antenna jack and keep the FMI trace as short as possible.
8. V_A and V_D may be supplied from the same V_BAT or may be supplied by independent power supplies.
9. Place R1 on the opposite side of the PCB as the tuner (as close to pin 15 as possible), and route the GPO trace to the
system controller on this layer.
3. Bill of Materials
Component(s)
C1
R1
U1
Value/Description
Supply bypass capacitor, 22 nF, ±20%, Z5U/X7R
GPO resistor, 1 k
Si4708/09 FM Radio Tuner
Supplier(s)
Murata
Venkel
Silicon Laboratories
12
Rev. 1.2