Application Information
External Components
V
DD
R
6
SEE INSET
XTAL
C
5
V
SS
C
6
R
4
C
8
R
7
1
2
3
4
5
6
7
8
9
24
23
22
21
20
V
DD
WAKE
NOTONE
COMPARATOR OUT
COMPARATOR IN (+)
COMPARATOR IN (-)
V
BIAS
Rx SUB-AUDIO OUT
C
3
R
3
D
1
XTAL/CLOCK
ADDRESS SELECT
IRQ
SERIAL CLOCK
COMMAND DATA
CS
REPLY DATA
R
8
FX805J
19
18
17
Tx SUB-AUDIO OUT
C
7
Rx SUB-AUDIO IN
*
16
15
14
13
D
2
AUDIO IN
AUDIO OUT
Rx AMP OUT
Rx AMP IN (+)
Rx AMP IN (-)
R
2
10
11
12
V
SS
R
5
C
4
V
SS
INSET
XTAL
Component
1
Value
1.0MΩ
360kΩ
10.0kΩ
150kΩ
100kΩ
150kΩ
22.0kΩ
360kΩ
R
9
R
10
R
11
C
1
C
2
C
3
C
4
C
5
=
Fig.4
Fig.4
Fig.4
33.0pF
33.0pF
1.5µF
15.0µF
1.0µF
C
6
C
7
C
8
C
9
D
1
D
2
X
1
1.0µF
0.1µF
1.0µF
Fig.4
silicon small sig
silicon small sig
f
XTAL
4.00MHz
=
X
R
1
1
FX805J
C
2
C
1
XTAL/CLOCK
V
SS
2
R
1
R
2
R
3
R
4
R
5
R
6
R
7
R
8
=
Fig.2 Recommended External Components
Notes
on external components and connections
1.
Xtal/clock circuitry components shown INSET are
recommended in accordance with CML Application Note
D/XT/2 December 1991. The DBS 800 System
Information Document contains additional notes on Xtal/
clock distribution and frequencies.
R
8
is a System Component. Its value is chosen, for
example, with the FX806 Modulation Summing
Amplifier, to provide a sub-audio signal level of -11.0dB
to the system modulator.
Components R
6
and C
6
are N
OTONE
timing components.
4.
5.
R
2
and R
5
are dependant upon the input signal level.
Values given are for the specified composite signal.
R
7
is used as the DBS 800 system common-pullup for
the “C-BUS” Interrupt Request (IRQ) line, the optimum
value of this component will depend upon the circuitry
connected to the IRQ line.
2.
3.
FX805 Rx LPF
FX805
Rx AMP
17
14
Rx AMP IN
13
FX805
COMPARATOR
HYSTERESIS
+
–
R
2
D.C. RESTORATION
15
R
3
D
2
D
1
20
COMPARATOR IN
19
R
4
16
C
3
+
21
–
Rx Sub-Audio Input
R
5
C
4
COMPARATOR OUT
V
SS
Fig.3 Employment of FX805 Input Components
With reference to Figure 2, Figures 3 and 4 show in detail recommended alternative component configurations for the FX805.
4
CMLMICRO [ CML MICROCIRCUITS ]
