EVB72036
868/915MHz FSK/ASK Transmitter
Evaluation Board Description
3 50Ω Connector Board Circuit Diagram
Fig. 6: Circuit diagram with 50 Ω matching network
3.1 Board Component Values
Value @
868.3 MHz
Value @
915 MHz
Toler-
ance
Part
Size
Description
CM1
CM2
CM3
LM
0805
0805
0805
0805
0805
0805
0805
0805
0805
0805
0805
1206
0805
1.8 pF
5.6 pF
68 pF
12 nH
15 nH
22 pF
27 pF
12pF
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 r
impedance matching inductor
output tank inductor
±5%
±5%
±5%
±5%
±5%
±5%
±5%
±5%
±5%
±5%
±5%
±20%
±10%
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 for FSK
capacitor to control clock voltage swing (CKDIV 0 / 1)
power-select resistor, see data sheet section 4.6
ASK jumper (for ASK only), see data sheet sect. 4.7
de-coupling capacitor
CCK
RPS
R1
15 pF/ 180 pF
NIP
0 Ω
220 nF
330 pF
CB0
CB1
de-coupling capacitor
XTAL
SMD
6x3.5
27.13438 MHz 28.59375 MHz
±30ppm cali., ±30ppm temp
1 nF
fundamental mode crystal,
CL = 12 pF, C0, max = 7 pF, R1 = 40 Ω
CK
0805
ROI coupling capacitor, only required for
external reference frequency input
±10%
Note 1: depends on crystal parameters, other ∆f values can be selected with other CX1, CX2 values
NIP – not in place, may be used optionally
3901272036 01
Rev. 002
Page 7 of 12
EVB Description
June/07
MELEXIS [ Melexis Microelectronic Systems ]
