si4021 Silicon Laboratories, si4021 Datasheet - Page 28

• Manufacturer Part Number: si4021
• Description: Si4021 Universal Ism Band Fsk Transmitter
• Manufacturer: Silicon Laboratories

MATCHING NETWORK FOR A 50 OHM SINGLE ENDED OUTPUT
Matching Network Schematic
Note 1:
Note 2:
Note 3:
and VSS pins
433 MHz
868 MHz
915 MHz
Si4021
1 mm thick board
1.5 mm thick board
C4 must be connected parallel to the supply decoupling capacitors (10nF + 2.2µF recommended) as close as possible to the VDD
L1 [nH]
5.1
4.3
16
L2 [nH]
47
24
24
L3 [nH]
390
100
100
L4 [nH]
5.1
4.3
16
(Note 1)
C1 [pF]
3.3
2
2
(Note 2)
C1 [pF]
3.3
1.5
1.8
C2 [pF]
6.0
2.2
2.2
C3 [pF]
2.7
1.2
1.2
IA4221
(Note 3)
C4 [pF]
220
47
33
28