SI4820-A10 Datasheet, PDF (9/20 Pages) Silicon Laboratories – BROADCAST MECHANICAL TUNING AM/FM/SW RADIO RECEIVER

2. Typical Application Schematic
Si4820/24-A10
FMI
C5
AMI
0.47u
ANT2
C5
AMI
0.47u
RFGND
T1
Optional: AM air loop antenna
R1
100k
C1
0.1u
TUNE1
SW
S2
VR1
100k
BAND 1
2
3 AM
4
R3
143k
R6
110k
R4
180k
FM
R5
67k
U1
C4
0.1u
Y1
32.768KHz
C3
C2
22p
22p
AOUT
VDD
2.0 TO 3.6V
VDD
2.0 TO 3.6V
Optional
Notes:
1. Place C₄ close to V_DD2 and DBYP pins.
2. All grounds connect directly to GND plane on PCB.
3. Pin 6, pin 7, and pin 23 leave floating.
4. To ensure proper operation and receiver performance, follow the guidelines in "AN555: Si483x-B/Si4820/24 Antenna,
Schematic, Layout, and Design Guidelines." Silicon Labs will evaluate the schematics and layouts for qualified
customers.
5. Pin 8 connects to the FM antenna interface and pin 12 connects to the AM antenna interface.
6. Place Si4820/24 as close as possible to antenna jack and keep the FMI and AMI traces as short as possible.
7. Recommend keeping the AM ferrite loop antenna at least 5 cm away from the tuner chip.
8. Keep the AM ferrite loop antenna at least 5 cm away from MCU, audio AMP, and other circuits which have AM
interference.
9. Place the transformer T1 away from any sources of interference and even away from the I/O signals of the Si4820/24.
Rev. 1.0
9