XE1202AI027TRLF Semtech, XE1202AI027TRLF Datasheet - Page 28

• Manufacturer Part Number: XE1202AI027TRLF
• Description: Narrow Band 433/868/915MHz RF Transceiver
• Manufacturer: Semtech

The schematic of the recommended matching network at the output of the transmitter is given in Figure 16 below.
The two Π-sections are used to provide harmonic filtering for passing FCC and ETSI regulations:
The typical component values of this matching circuit are given Table 27 below:
6.3 VCO tank
The tank of the VCO is implemented with an inductor in parallel with an (optional) capacitor. The recommended
values for these components are given in Table 28 below:
In order to optimize the tuning range of the VCO, the value of the inductance should be as high as possible and
external capacitance must be avoided if possible. It is recommended that the PCB layout includes two ‘footprints’ in
order to place two inductances in parallel; this enables the tank of the VCO to be centered more precisely.
© Semtech 2006
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Name
CT1
CT2
CT3
CT4
CT5
LT1
LT2
LT3
Name
CR1
LR1
Typical Value
LT3
for 434 MHz
6.8 pF
1.0 pF
6.8 pF
4.7 pF
33 nH
22 nH
22 nH
22 pF
Table 27: Matching circuit component values
39 nH ± 2 %
Table 28: VCO tank component values
Figure 16: Transmitter output network
434 MHz
NC
CT3
Typical Value
for 869 MHz
29
0.56 pF
8.2 nH
1.5 pF
3.3 pF
2.2 pF
39 nH
10 nH
15 pF
6.8 nH ± 2 %
869 MHz
NC
LT2
CT2
XE1202A TrueRF™
Typical Value
for 915 MHz
1.8 pF
3.3 pF
2.2 pF
8.2 nH
47 nH
10 nH
33 pF
NC
VDD
5.6 nH ± 2 %
915 MHz
NC
Tolerance
± 5 %
± 5 %
± 5 %
± 5 %
± 5 %
± 5 %
± 5 %
± 5 %
XE1202A
TrueRF™
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