External Components
VDD
C5
SEE INSET
R4
VDD
XTAL
1
2
3
4
24
XTAL/CLOCK
IRQ
WAKE
23
22
21
20
ADDRESS SELECT
SERIAL CLOCK
COMMAND DATA
CS
5
6
Rx FREEFORMAT
19
18
17
16
15
14
13
FX809J
VBIAS
7
8
R2
C 6
R3
SIGNAL IN
C7
REPLY DATA
SIGNAL OUT
9
Rx IN
10
C 4
11
12
VSS
Tx OUT
C 3
VSS
INSET
Component
Value
1.0MΩ
Note 1
100kΩ
22.0kΩ
33.0pF
33.0pF
1.0µF
0.1µF
1.0µF
33.0pF
Note 1
4.032MHz
XTAL
1
R1
R2
R3
R4
C1
C2
C3
C4
C5
C6
C7
X1
=
Note 1:
R2, R3 and C7 form the gain
components for the signal;
R3 should be chosen as
required by the signal input
level.
R 1
X1
FX809J
2
XTAL/CLOCK
VSS
C2
C1
Fig.2 External Components
Tolerance: R = ±10% C = ±20%
Modem Performance
2 x 10-2
Bit Error Rate
(Logarithmic Scale)
10-2
Ideal Coherent FFSK
Characteristic
FX809
Characteristic
10 -3
10 -4
8
6
4
3
2
10 -5
(Linear Scale )
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Signal to Noise Ratio (dB) [Bit-Rate Bandwidth]
Fig.3 Bit Error Rate vs Signal-to-Noise Ratio
CMLMICRO [ CML MICROCIRCUITS ]
