+5V-Powered, Multichannel RS-232
Drivers/Receivers
TOP VIEW
+5V INPUT
1.0µF
1.0µF
1.0µF
9
10
V
11
15
CC
C1+
V+
V-
+5V TO +10V
VOLTAGE DOUBLER
1.0µF
1.0µF
12
13
C1-
C2+
+10V TO -10V
VOLTAGE INVERTER
14
C2-
+5V
+5V
+5V
+5V
400kΩ
T1
T3
T1
T2
1
2
3
4
5
6
7
8
9
24 T4
23 R2
22 R2
T1
T1
7
2
OUT
OUT
OUT
OUT
OUT
IN
IN
400kΩ
OUT
IN
T2
OUT
T2
T3
6
3
1
IN
IN
T2
R1
21 T5
20 T5
19 T4
18 T3
17 R3
16 R3
15 V-
IN
MAX237
R1
OUT
OUT
IN
400kΩ
T2
IN
T3
18
OUT
TTL/CMOS
INPUTS
RS-232
OUTPUTS
T3
T1
IN
IN
400kΩ
GND
OUT
IN
T4
T5
24
20
4
19 T4
21 T5
OUT
IN
V
T4
CC
+5V
C1+ 10
V+ 11
400kΩ
14 C2-
13 C2+
OUT
IN
T5
C1- 12
DIP/SO
5
R1
R1
IN
OUT
OUT
OUT
R1
5kΩ
22
R2
R2
R3
23
16
IN
RS-232
INPUTS
TTL/CMOS
OUTPUTS
R2
R3
5kΩ
R3
17
IN
5kΩ
GND
8
Figure 15. MAX237 Pin Configuration and Typical Operating Circuit
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