Datasheet

MAX220–MAX249
+5V-Powered, Multichannel RS-232
Drivers/Receivers
32 ______________________________________________________________________________________
400k
Ω
V
CC
400k
Ω
GND
+5V
+5V
+5V
+5V
+5V
1
40
16
1
μ
F
2
18
4
5k
Ω
5k
Ω
5k
Ω
5k
Ω
5k
Ω
5k
Ω
5k
Ω
5k
Ω
ENTA
T
A1
OUT
T
A1
IN
T
A3
OUT
T
A3
IN
6R
B5
OUT
12 R
A1
IN
10 R
A1
OUT
13 R
A2
IN
9R
A2
OUT
14 R
A3
IN
8R
A3
OUT
15 R
A4
IN
7
20
R
A4
OUT
11
39
24
38
22
36
29
31
28
32
27
33
26
34
30ENRA
ENTB
T
B1
OUT
T
B1
IN
T
B3
OUT
T
B3
IN
R
B1
IN
5k
Ω
25
R
B5
IN
R
B1
OUT
R
B2
IN
R
B2
OUT
R
B3
IN
R
B3
OUT
R
B4
IN
R
B4
OUT
ENRB
400k
Ω
+5V
17
3
T
A2
OUT
T
A2
IN
+5V
23
37
T
B2
OUT
T
B2
IN
400k
Ω
+5V
19
5
T
A4
OUT
T
A4
IN
+5V
21
35
T
B4
OUT
T
B4
IN
40
V
CC
ENTB
T
B1
IN
T
B2
IN
T
B3
IN
T
B4
IN
R
B4
OUT
R
B3
OUT
R
B2
OUT
R
B1
OUT
R
B1
IN
R
B2
IN
R
B3
IN
R
B4
IN
R
B5
IN
T
B1
OUT
T
B2
OUT
T
B3
OUT
T
B4
OUT
39
38
37
36
35
34
33
32
31
1
2
3
4
5
6
7
8
9
10
ENTA
T
A1
IN
T
A2
IN
T
A3
IN
T
A4
IN
R
B5
OUT
R
A4
OUT
R
A3
OUT
R
A2
OUT
R
A1
OUT
R
A1
IN
R
A2
IN
R
A3
IN
R
A4
IN
T
A1
OUT
T
A2
OUT
T
A3
OUT
T
A4
OUT
GND
TOP VIEW
MAX247
30
29
28
27
26
25
24
23
22
21
11
12
13
14
15
16
17
18
19
DIP
20
ENRA ENRB
MAX247 FUNCTIONAL DESCRIPTION
9 RECEIVERS
4 A-SIDE RECEIVERS
5 B-SIDE RECEIVERS (R
B5
ALWAYS ACTIVE)
8 TRANSMITTERS
4 A-SIDE TRANSMITTERS
4 B-SIDE TRANSMITTERS
4 CONTROL PINS
ENABLE RECEIVER A-SIDE (ENRA)
ENABLE RECEIVER B-SIDE (ENRB)
ENABLE RECEIVER A-SIDE (ENTA)
ENABLE RECEIVER B-SIDE (ENTB)
Figure 23. MAX247 Pin Configuration and Typical Operating Circuit