Silicon Laboratories SI4734/35-B20 Typical Application Schematic, Si4734/35-GM, Si4734/35-B20

Si4734/35-B20

2. Typical Application Schematic

GPO1

GPO2/INT

R1

DCLK

R2

DFS

20

19

18

17

16

1

NC

GPO1

GPO2 GPO3

DFS

DOUT 15

R3

DOUT

NC

Optional: Digital Audio Output

FMI

C4

2

FMI

3

RFGND

LOUT 14

LOUT

U1

L2

L1

ROUT

13

ROUT

Si4734/35-GM

GND

12

4

C5

AMI

VDD

11

5

RST

VBATTERY

C1

SCLK

SDIO RCLK

2.7 to 5.5 V

SEN

VIO

RST

6 7 8 9

10

GPO3

X1

RCLK

SEN

SCLK

C2

C3

SDIO

RCLK

Optional: for crystal oscillator option

VIO

1.5 to 3.6 V

Notes:

1.Place C1 close to VDD 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: Antenna Selection and Universal Layout Guide.” 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 Si4734/35 as close as possible to antenna jack and keep the FMI and AMI traces as short as possible.

8.See “AN382: Si4734/35 Designer’s Guide” for further recommendations.

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