EVB72005
315MHz FSK/ASK Transmitter
Evaluation Board Description
4 50
Ω
Connector Board Circuit Diagram
OUT
CM2
LM
CM3
CM1
CB1
10
LT
9
8
7
6
VEE
VCC
OUT
VEE
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. 7:
Circuit diagram with 50
Ω
matching network
ASKD
FSKD
ENTX
ROI
PSEL
5
RPS
4.1
Board Component Values to Fig. 7
Size
0805
0805
0805
0805
0805
0805
0805
0805
0805
1206
0805
HC49/S
0805
Part
CM1
CM2
CM3
LM
LT
CX1
_FSK
CX1
_ASK
CX2
RPS
CB0
CB1
XTAL
CK
Value
@ 315 MHz
10 pF
15 pF
82 pF
47 nH
33 nH
15 pF
27 pF
47 pF
NIP
220 nF
330 pF
Tolerance
±5%
±5%
±5%
±5%
±5%
±5%
±5%
±5%
±5%
±20%
±10%
Description
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, R
1
= 60
Ω
ROI coupling capacitor,
only required for external reference frequency input
9.84375MHz
±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 72005 01
Rev. 007
Page 9 of 14
EVB Description
June/07
RO
ENTX
VCC
MELEXIS [ Melexis Microelectronic Systems ]
