TH72035_12 Datasheet, PDF (17/20 Pages) Melexis Microelectronic Systems – FSK/ASK Transmitter

6 Test Circuit
TH72035
868/915MHz
FSK/ASK Transmitter
CM2
CM1
OUT
LM
CM3
LT
RPS
CB1
10 9 8 7 6
1
CB0
23 4
CX2
CX1
5
XTAL
12 12 3 4
12 3
Fig. 18: Test circuit for FSK and ASK with 50 Ω matching network
6.1 Test circuit component list to Fig. 18
Part
Size
Value @
868.3 MHz
Value @
915 MHz
Tolerance
Description
CM1
CM2
CM3
LM
LT
CX1_FSK
CX1_ASK
CX2
RPS
CB0
CB1
XTAL
0805
0805
0805
0805
0805
0805
0805
0805
0805
0805
0805
HC49/S
1.8 pF
5.6 pF
68 pF
12 nH
15 nH
18 pF
27 pF
10 pF
2.2 pF
5.6 pF
68 pF
10 nH
10 nH
18 pF
27 pF
10 pF
see section 4.6
220 nF
330 pF
27.13438 MHz 28.59375 MHz
±5%
impedance matching capacitor
±5%
impedance matching capacitor
±5%
impedance matching capacitor
±5%
impedance matching inductor, note 2
±5%
output tank inductor, note 2
±5%
XOSC FSK capacitor (∆f = ±20 kHz), note 1
±5%
XOSC ASK capacitor, trimmed to fC, note 1
±5%
XOSC capacitor (∆f = ±20 kHz), note 1
only needed for FSK
±5%
power-select resistor
±20%
de-coupling capacitor
±10%
de-coupling capacitor
±30ppm calibr. fundamental wave crystal,
±30ppm temp. CL = 12 pF, C0, max = 7 pF, R1 = 40 Ω
Note 1: value depending on crystal parameters
Note 2: for high-power applications high-Q wire-wound inductors should be used
39010 72035
Rev. 011
Page 17 of 20
Data Sheet
Jan/12