TDA5250D2_07 INFINEON [Infineon Technologies AG], TDA5250D2_07 Datasheet - Page 43

• Manufacturer Part Number: TDA5250D2_07
• Description: ASK/FSK 868MHz Wireless Transceiver
• Manufacturer: INFINEON [Infineon Technologies AG]

Figure 3-4
R1 does not influence the matching because of its very high resistance. Due to the large
capacitance of C1, C6 and C5 the circuit can be further simplified for RF:
Figure 3-5
The LNA-matching is RF-grounded now, so no power is lost in the LNA-input. The PA-matching
consists of C2, C3 L2, C4 and L1.
When designing the matching of the PA, C2 must not be changed anymore because its value is
already fixed by the LNA-input-matching.
Data Sheet
TX_Mode
TX_Mode_simplified
SMA-connector
50 Ohm
RX/TX-pin of IC)
(with jumper or
RF I/O
SMA-connector
grounded
50 Ohm
RF I/O
C2
RX/TX
C2
C1
C7
R1
C6
C3
C7
43
C3
L3
L2
C9
L3
L2
C4
C9
L1
C10
C4
L1
C10
VCC
LNI
LNIX
PA
C5
RX/TX
LNI
PA
LNIX
TDA5250 D2
TX_Mode_simplified.wmf
Version 1.7
Application
2007-02-26
TX_Mode.wmf