SI4739-B20-GMR Datasheet, PDF (15/24 Pages) Silicon Laboratories – BROADCAST MULTI-BAND RADIO RECEIVER

3. Typical AM/FM Application Schematic
Si473x-B20
FMIP
L1
AM antenna
C5
GPO1
GPO2/INT
R1
GPO3/DCLK
R2
DFS
1 _NC
2 _FMI
3 _RFGND
4 _AMI
5 _RST
DOUT ^{15 R3}
DOUT
Optional: Digital Audio Output
U1
Si473x-GM
LOUT/DFS ¹⁴
ROUT/DOUT ¹³
GND ¹²
VDD ¹¹
LOUT
ROUT
C1
VBATTERY
2.7 to 5.5 V
RST
SEN
SCLK
SDIO
RCLK
VIO
1.5 to 3.6 V
GPO3
X1
RCLK
C2
C3
Optional: for crystal oscillator option
L2
RFGND
AMI
T1
C5
Optional: AM air loop antenna
Notes:
1. Place C1 close to V_DD pin.
2. All grounds connect directly to GND plane on PCB.
3. Pins 1 and 20 are no connects, leave floating.
4. To ensure proper operation and receiver performance, follow the guidelines in “AN383: Si47xx Antenna, Schematic,
Layout and Design Guidelines.” Silicon Laboratories will evaluate schematics and layouts for qualified customers.
5. Pin 2 connects to the FM antenna interface and pin 4 connects to the AM antenna interface.
6. RFGND should be locally isolated from GND.
7. Place Si473x as close as possible to antenna jack and keep the FMI and AMI traces as short as possible.
Rev. 0.5
15