FX506 Datasheet, PDF (4/17 Pages) Sanyo Semicon Device – High-Current Switching Applications

External Components and Interfacing
V _DD
C₉
V_SS
XTAL
1
24
X₁
2
23
XTAL/CLOCK
V_DD
3
22
POST PROCESS
C₇
AUDIO INPUT
4
21
PRE-PROCESS AUDIO OUTPUT
Rx
C₆
AUDIO INPUT
5
6
V_BIAS
7
20
FX506P ¹⁹
18
CTCSS/DATA INPUT
8
17
Tx AUDIO INPUT
9
16
SEE
MIC. OUTPUT
10
15
FIG.3
MIC. INPUT 1
C₃
BELOW
11
14
MIC. INPUT 2
12
13
C₄
C₁
V_SS
Fig.2 Recommended External Components
CHIP SELECT
R₂
SERIAL DATA INPUT
SERIAL CLOCK INPUT
SQUELCH DRIVE
NOISE OUTPUT
R₄
NOISE INPUT
R.S.S.I.
VCO DRIVE (Tx)
VCO REF. DRIVE (Tx)
C₅
AUDIO OUTPUT (Rx)
COMPRESSION
CAPACITOR
V_SS
C₈
C₂
R₁
R₃
V_BIAS
MIC. I/P
1
11 ^{MIC. O/P}
10
C _3/C4
12
MIC. I/P
2
R₆
R₅
BIAS
C₁₀
–
+
EXTERNAL
OP-AMP
Tx
AUDIO INPUT
9
Fig.3 Typical 2nd Order Pre-emphasis Input Circuit
Notes
For dual Tx inputs using both Mic.1 and Mic.2 inputs without
pre-emphasis, capacitors C and C will be required at the
3
4
inputs as shown in Figure 2.
If pre-emphasis is required, the external circuit shown in
Figure 3 is recommended.
The Op-Amp selected for this application should be of a “low
noise wide-bandwidth” type i.e. with at least 60dB of gain at
6kHz.
In addition to the components shown in Figure 2, it is
recommended that the power and V_BIAS lines to the external
Op-Amp are decoupled to V physically close to the
SS
amplifier, by a 1.0µF capacitor.
Circuit References
Component
R=
1
R
2
R
3
R
4
R
5
R
6
Value
100kΩ
390kΩ
100kΩ
10kΩ
18.0kΩ
2.7MΩ
Tolerance
= ± 10%
± 10%
± 1%
± 10%
± 1%
± 1%
C₁ =
C
2
C₃
C
4
C₅
C
6
1.0µF
6.8µF
1.0nF
1.0nF
15nF
0.1µF
± 20%
± 20%
± 1%
± 1%
± 1%
± 20%
C₇ =
C
8
C₉
C
10
X
1
0.1µF
0.1µF
1.0µF
12.0pF
4.0MHz
± 20%
± 20%
± 20%
± 1%
Layout Recommendations
Audio microcircuit performance will be affected by external
noise.
All external components should be kept as close to
the device as possible.
Tracks to the device should be kept short, particularly
the Audio and V inputs.
BIAS
A “ground-plane” connected to V will help to
SS
eliminate external pick-up.
Ensure that all inputs (analogue and d.c.) are free from
noise.
Xtal/clock and digital tracks should be kept well away
from analogue circuitry. Analogue inputs and outputs
should be screened wherever possible with high-level
outputs isolated from very low-level inputs.
4