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Si4421
Evaluation Board with Resonant PCB Antenna (BIFA)
Schematics
*
*
* See values in the table
L1
12
34
56
78
910
11 12
13 14
15 16
17 18
19 20
21 22
23 24
25 26
27 28
29 30
31 32
33 34
35 36
37 38
39 40
CS1
C6
C3 C2
Q1
ARSSI
C4
TP1
C1
FFS/DATA
SEL
SCK
SDI
SDO
IRQ
FFE
VDI
1
2
3
JP1
TP3
SDI
1
SCK
2
NSEL
3
SDO
4
NIRQ
5
FSK/DATA/NFFS
6
DCLK/CFIL
7
NINT/VDI
16
XTL/REF
9
CLK
8
VSS
11
RF2
12
RF1
13
VDD
14
ARSSI
15
NRES
10
IC1
CLK_OUT
R6
R7
R5
R8
ARSSI
RESET
RESET
SDI
SDI
SCK
SCK
SEL
SEL
SDO
SDO
IRQ
IRQ
DATA
DATA
DATA
DATA DCLK
DCLK
DCLK
DTO
DTO
CLKIN
CLKIN
VDI
VDI
VDI
CON40-0
100pF
10nF
GND
GND
GND
GND
10MHz
VDD
VDD
10nF
GND
2.2uF
GND
IA4421
10k
100k
10k
10k
Note: Components R5 to R8 and C6 are needed for connection to the ISM Chipset Development Kit load board (IA ISM-DK3) and are
not necessary in an application.
Frequency Dependent Component Values
Band C3 [pF] L1 [nH]
868 MHz 47 22
Dual (868/915 MHz) 47/33 18
915 MHz 33 15
41