+5V-Powered, Multichannel RS-232
Drivers/Receivers
TOP VIEW
+5V INPUT
1.0µF
9
1.0µF
1.0µF
10
V
CC
11
15
C1+
V+
V-
+5V TO +10V
VOLTAGE DOUBLER
1.0µF
1.0µF
12
13
C1-
C2+
+10V TO -10V
VOLTAGE INVERTER
14
C2-
+5V
400kΩ
T1
T1
T1
5
18
19
2
T2
T1
1
2
3
4
5
6
7
8
9
24 T3
23 R3
22 R3
OUT
IN
OUT
OUT
+5V
+5V
OUT
IN
400kΩ
R2
IN
OUT
IN
T2
OUT
T2
IN
T3
IN
1
T2
R2
OUT
21 T4
20 T4
19 T3
18 T2
17 R4
16 R4
15 V-
TTL/CMOS
INPUTS
RS-232
OUTPUTS
MAX238
T1
IN
OUT
IN
400kΩ
R1
OUT
T3
OUT
24
T3
400kΩ
T4
R1
IN
IN
+5V
GND
OUT
IN
T4
20
V
21 T4
OUT
CC
IN
C1+ 10
V+ 11
14 C2-
13 C2+
R1
C1- 12
6
4
R1
IN
7
3
OUT
R1
R2
5kΩ
R2
DIP/SO
R2
OUT
IN
TTL/CMOS
OUTPUTS
5kΩ
R3
RS-232
INPUTS
R3
R4
23
16
22
17
OUT
OUT
IN
IN
R3
R4
5kΩ
R4
5kΩ
GND
8
Figure 16. MAX238 Pin Configuration and Typical Operating Circuit
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