PvtSQUELCH
TM
CTCSS Encoder/Decoder
6
MX375
3. External Components
+5V
C1 +
D5
D4
D3
D2
D1
D0
V
SS
1
R1
2
X1
C3
3
LOAD/LATCH
4
5
6
7
8
9
10
CTCSS TONE
DECODE OUTPUT
11
C10
D1
R3
12
R2
13
NOTONE
14
C2
MX375J/P/LH8
XTAL
XTAL
LOAD/LATCH
D5
D4
D3
D2
D1
D0
RX DECODE
COMP IN
DETECT
NOTONE
V
SS
V
DD
RXTONE
PRIVEN
RX/TX
CONTROL
PTL
TXIN
RXIN
TXOUT
RXOUT
BALMOD
FILTER
BIAS
TXTONE
28
27
26
25
24
23
22
21
20
19
18
17
16
15
C5
V
DD
CTCSS TONE IN (RX)
PRIVACY ENABLE
PUSH TO TALK
MODE SELECTION
PUSH TO LISTEN
C11
C6
C12
C8
TX AUDIO IN
RX AUDIO IN
TX AUDIO OUT
RX AUDIO OUT
C4
BIAS
C9
CTCSS TONE
OUTPUT (TX)
C7
+
C13
Figure 2: Recommended External Components
R1
R2
R3
X1
C1
C2
C3
C4
C5
Note 1, 2
1MΩ
560kΩ
820kΩ
4MHz
1.0µF
33pF
33pF
0.1µF
0.1µF
±10%
±10%
±10%
±20%
±20%
±20%
±20%
±20%
C6
C7
C8
C9
C10
C11
C12
C13
D1
0.1µF
1.0µF
0.1µF
0.1µF
0.1µF
0.1µF
0.1µF
0.001µF
small signal
±20%
±20%
±20%
±20%
±20%
±20%
±20%
±20%
Table 2: Recommended External Components
Recommended External Components Note:
1. For best results, a crystal oscillator design should drive the clock inverter input with signal levels of at least 40% of
V
DD
, peak to peak. Tuning fork crystals generally cannot meet this requirement. To obtain crystal oscillator design
assistance, consult your crystal manufacturer.
2. XTAL - At cut, fundamental, parallel resonant 20pF load capacitance, 0.05% tolerance
© 1997 MX•COM Inc.
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
www.mxcom.com Tele: 800 638-5577 910 744-5050
All trademarks and service marks are held by their respective companies.
Fax: 910 744-5054
Doc. # 20480026.007
CMLMICRO [ CML MICROCIRCUITS ]
