TH72036
868/915MHz
FSK/ASK Transmitter
5 Test Circuit
CM1
CM2
LM
RPS
7
LT
CM3
10
OUT
CB1
9
8
6
1
2
3
4
5
R1
CX1
CB0
1 2
1 2
1 2
1 2
1 2
1
2
3
Fig. 6: Test circuit for FSK and ASK with 50 Ω matching network
5.1 Test circuit component list to Fig. 6
Part
Size
Value @
868.3 MHz
Value @
915 MHz
Tolerance
Description
CM1
CM2
0805
0805
0805
0805
0805
0805
0805
0805
1.8 pF
5.6 pF
68 pF
12 nH
15 nH
22 pF
27 pF
12 pF
2.2 pF
5.6 pF
68 pF
10 nH
10 nH
22 pF
27 pF
12 pF
impedance matching capacitor
impedance matching capacitor
impedance matching capacitor
impedance matching inductor, note 2
output tank inductor, note 2
±5%
±5%
±5%
±5%
±5%
±5%
±5%
±5%
CM3
LM
LT
CX1_FSK
CX1_ASK
CX2
XOSC FSK capacitor (Δf = ±20 kHz), note 1
XOSC ASK capacitor, trimmed to fC, note 1
XOSC capacitor (Δf = ±20 kHz), note 1
only needed for FSK
CCK
RPS
R1
0805
0805
15 pF / 180 pF
clock spur suppression capacitor, CKDIV 0 / 1
FSK or CW mode power-select resistor
ASK power-select resistor, not used at FSK
de-coupling capacitor
±5%
±5%
see section 4.6
see section 4.7
CB0
CB1
XTAL
0805
0805
220 nF
±20%
±10%
330 pF
de-coupling capacitor
SMD
6x3.5
27.13438 MHz 28.59375 MHz
fundamental wave crystal,
CL = 12 pF, C0, max = 7 pF, R1 = 40 Ω
±30ppm calibr.
±30ppm temp.
Note 1: value depending on crystal parameters
Note 2: for high-power applications high-Q wire-wound inductors should be used
3901072036
Rev. 005
Page 12 of 16
Data Sheet
June/07
MELEXIS [ Melexis Microelectronic Systems ]
