EVB72035 Datasheet, PDF (9/14 Pages) Melexis Microelectronic Systems – 868/915MHz FSK/ASK Transmitter Evaluation Board Description

EVB72035
868/915MHz FSK/ASK Transmitter
Evaluation Board Description
4 50Ω Connector Board Circuit Diagram
OUT
CM2
LM
CM3
CM1
CB1
LT
10 9 8 7 6
RPS
Fig. 7: Circuit diagram with 50 Ω matching network
123 4 5
CX2
XTAL
CB0
CX1
CK
12345 6
12 3
45 6
4.1 Board Component Values to Fig. 7
Part
Size
Value @
868.3 MHz
Value @
915 MHz
Toler-
ance
Description
CM1
CM2
CM3
LM
LT
CX1_{_FSK}
CX1_{_ASK}
CX2
0805
0805
0805
0805
0805
0805
0805
0805
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
RPS
CB0
CB1
XTAL
CK
0805
1206
0805
HC49/S
0805
NIP
220 nF
330 pF
27.13438 MHz 28.59375 MHz
±30ppm cali., ±30ppm temp
1 nF
±5%
±5%
±5%
±5%
±5%
±5%
±5%
±5%
±5%
±20%
±10%
±10%
impedance matching capacitor
impedance matching capacitor
impedance matching capacitor
impedance matching inductor
output tank inductor
XOSC FSK capacitor (Δf = ±20 kHz), note 1
XOSC ASK capacitor, trimmed to f_C, note 1
XOSC capacitor (Δf = ±20 kHz), note 1,
only needed for FSK
power-select resistor, see data sheet section 4.6
de-coupling capacitor
de-coupling capacitor
fundamental mode crystal,
C_L = 12 pF, C_{0, max} = 7 pF, R₁ = 40 Ω
ROI coupling capacitor, only required for
external reference frequency input
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
39012 72035 01
Rev. 007
Page 9 of 14
EVB Description
June/07