SI4704 Datasheet, PDF (16/36 Pages) Silicon Laboratories – Worldwide FM band support (64-108 MHz) integrated antenna support EN55020 compliant

Si4704/05-C40
2. Typical Application Schematic
1 _NC
FMI
2 _FMI
3 _RFGND
U1
Si4704/05
LPI
4 _LPI
5 _RST
GPO1
GPO2/INT
R1
GPO3/DCLK
R2
DFS
DOUT ^{15 R3}
DOUT
Optional: Digital Audio Output
LOUT ¹⁴
ROUT ¹³
GND ¹²
VDD ¹¹
LOUT
ROUT
C1
VBATTERY
2.7 to 5.5 V
RST
SEN
SCLK
SDIO
RCLK
VIO
1.85 to 3.6 V
GPO3
X1
RCLK
C2
C3
Optional: for crystal oscillator option
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 or Pin 4 connects to the FM antenna interface. Pin 2 is for a headphone antenna. Pin 4 is for an integrated
antenna.
6. Place Si4704/05 as close as possible to antenna and keep the FMI and LPI traces as short as possible.
16
Rev. 1.0