EVB72015
433MHz FSK/ASK Transmitter
Evaluation Board Description
3 Antenna Board Circuit Diagram
PCB loop antenna
CB1
VEE
VCC
OUT
VEE
10
LM2
LM1
CM2
CM1
9
8
7
6
ASKDTA
FSKDTA
FSKSW
1
2
3
4
CX2
CB0
CX1
XTAL
CK
1 2 3 4 5 6
1 2 3
4 5 6
VCC
GND
Fig. 6:
Circuit diagram with loop antenna matching network
ASKD
FSKD
ENTX
ROI
PSEL
5
RPS
3.1
Board Component Values to Fig. 6
Size
0603
0603
0603
0603
0805
0805
0805
0603
1206
0603
HC49/S
0805
Part
CM1
CM2
LM1
LM2
CX1
_FSK
CX1
_ASK
CX2
RPS
CB0
CB1
XTAL
CK
Value
@ 433.92 MHz
18 pF
3.3 pF
27 nH
68 nH
12 pF
27 pF
33 pF
NIP
220 nF
330 pF
Tolerance
±5%
±5%
±5%
±5%
±5%
±5%
±5%
±5%
±20%
±10%
Description
impedance matching capacitor
impedance matching capacitor
impedance matching inductor
impedance matching inductor
XOSC FSK capacitor (Δf =
±28
kHz), note 1
XOSC ASK capacitor, trimmed to f
C
, note 1
XOSC capacitor (Δf =
±28
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, R
1
= 60
Ω
ROI coupling capacitor,
only required for external reference frequency input
13.5600 MHz
±30ppm
cal.,
±30ppm
temp.
1 nF
±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
39012 72015 01
Rev. 007
Page 7 of 14
EVB Description
June/07
RO
EN
VCC
MELEXIS [ Melexis Microelectronic Systems ]
