+5V-Powered, Multichannel RS-232
Drivers/Receivers
+5V
TOP VIEW
1µF
40
V
CC
1 ENTA
ENTB 39
+5V
+5V
+5V
+5V
+5V
+5V
+5V
+5V
ENTA
1
2
3
4
5
6
7
8
9
40
39
38
37
36
35
34
33
32
31
V
CC
16 T OUT
A1
T
T
T
T
OUT 24
B1
T IN
A1
T IN
A2
T IN
A3
ENTB
400k
400k
2 T IN
A1
T
IN 38
B1
T
T
T
T
IN
IN
IN
B1
B2
B3
B4
17 T OUT
A2
OUT 23
B2
T IN
A4
R
OUT
OUT
OUT
OUT
B5
IN
3 T IN
A2
T
IN 37
B2
R
R
R
R
OUT
R
R
R
R
MAX247
B4
A4
A3
A2
A1
18 T OUT
OUT 22
B3
A3
OUT
OUT
OUT
B3
B2
400k
400k
4 T IN
A3
T
IN 36
B3
OUT 10
B1
19 T OUT
OUT 21
B4
A4
ENRA
ENRB
11
12
13
14
30
29
28
27
26
25
24
23
22
21
R
R
R
R
IN
IN
IN
R
R
R
R
R
IN
IN
IN
IN
IN
A1
B1
B2
B3
B4
B5
5 T IN
A4
T
IN 35
IN 25
B4
A2
6 R OUT
B5
R
B5
A3
5k
IN 15
A4
16
17
18
19
20
T
T
T
T
OUT
A1
OUT
A2
OUT
A3
OUT
A4
12 R IN
R
IN 29
B1
A1
T
T
T
T
OUT
OUT
OUT
OUT
B1
B2
B3
B4
5k
5k
5k
5k
5k
10 R OUT
R
OUT 31
A1
B1
GND
13 R IN
A2
R
IN 28
B2
DIP
5k
MAX247 FUNCTIONAL DESCRIPTION
9 RECEIVERS
9 R OUT
A2
R
OUT 32
B2
4 A-SIDE RECEIVERS
5 B-SIDE RECEIVERS (R ALWAYS ACTIVE)
B5
14 R IN
A3
R
IN 27
B3
8 TRANSMITTERS
5k
4 A-SIDE TRANSMITTERS
4 B-SIDE TRANSMITTERS
4 CONTROL PINS
8 R OUT
R
OUT 33
A3
B3
15 R IN
R
IN 26
B4
A4
ENABLE RECEIVER A-SIDE (ENRA)
ENABLE RECEIVER B-SIDE (ENRB)
ENABLE RECEIVER A-SIDE (ENTA)
ENABLE RECEIVERr B-SIDE (ENTB)
5k
7 R OUT
A4
R
OUT 34
B4
11 ENRA
ENRB 30
GND
20
Figure 23. MAX247 Pin Configuration and Typical Operating Circuit
32 ______________________________________________________________________________________