SI4736-B20 Datasheet, PDF (16/38 Pages) Silicon Laboratories – BROADCAST WEATHER BAND RADIO RECEIVER

Si4736/37/38/39-B20
2. Typical Application Schematic
FMIP
L1
AM antenna _C5
Si4736/37 only
1 _NC
2 _FMI
3 _RFGND
4 _AMI
5 _RST
GPO1
GPO2/INT
R1
GPO3/DCLK
R2
DFS
U1
Si473x
DOUT ^{15 R3}
DOUT
Optional: Digital Audio Output
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: Universal Antenna Selection and
Layout 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 Si4736/37/38/39 as close as possible to antenna jack and keep the FMI and AMI traces as short as possible.
16
Rev. 1.0