MAX220–MAX249
+5V-Powered, Multichannel RS-232
Drivers/Receivers
______________________________________________________________________________________ 29
400k
Ω
+10V TO -10V VOLTAGE INVERTER
+5V TO +10V VOLTAGE DOUBLER
V
CC
400k
Ω
400k
Ω
GND
+5V
+5V
+5V
+5V
+5V
25
24
23
21
20
2
1
µ
F
1
µ
F
1
µ
F
1
µ
F
1
µ
F
16
3
17
4
18
5k
Ω
5k
Ω
5k
Ω
5k
Ω
5k
Ω
5k
Ω
5k
Ω
5k
Ω
5k
Ω
5k
Ω
C2-
C2+
C1-
C1+
T
A2
OUT
T
A2
IN
T
A3
OUT
T
A3
IN
T
A4
OUT
T
A4
IN
9R
A1
IN
10 R
A1
OUT
8R
A2
IN
11 R
A2
OUT
7R
A3
IN
12 R
A3
OUT
6R
A4
IN
13 R
A4
OUT
5R
A5
IN
14
19
R
A5
OUT
26
22
43
29
42
28
41
27
36
35
37
34
38
33
39
32
40
31
V-
V+
T
B2
OUT
T
B2
IN
400k
Ω
2
15
T
A1
OUT
T
A1
IN
44
30
T
B1
OUT
T
B1
IN
T
B3
OUT
T
B3
IN
T
B4
OUT
T
B4
IN
R
B1
IN
R
B1
OUT
R
B2
IN
R
B2
OUT
R
B3
IN
R
B3
OUT
R
B4
IN
R
B4
OUT
R
B5
IN
R
B5
OUT
MAX249 FUNCTIONAL DESCRIPTION
10 RECEIVERS
5 A-SIDE RECEIVER
5 B-SIDE RECEIVER
8 TRANSMITTERS
4 A-SIDE TRANSMITTERS
4 B-SIDE TRANSMITTERS
NO CONTROL PINS
441234404142
43
5
21
24
26
25
27
28
22 2319
20
8
9
10
11
12
13
14
15
16
17
29
30
31
32
33
34
35
36
37
38
T
A3
IN
V
CC
R
A5
IN
MAX244
PLCC
TOP VIEW
T
A4
OUT
T
A3
OUT
T
A2
OUT
T
A1
OUT
T
B1
OUT
T
B2
OUT
T
B3
OUT
TB
4
OUT
R
B5
IN
GND
V+
C1+
C2+
C1-
V-
C2-
T
B3
IN
T
B4
IN
R
B3
IN
R
B2
IN
R
B1
IN
R
B1
OUT
R
B2
OUT
R
B3
OUT
R
B4
OUT
R
B5
OUT
T
B1
IN
T
B2
IN
T
A2
IN
T
A1
IN
R
A5
OUT
R
A4
OUT
R
A3
OUT
R
A2
OUT
R
A1
OUT
R
A1
IN
R
A2
IN
7
39
R
B4
IN
R
A3
IN
6
18
R
A4
INT
A4
IN
+5V
+5V
+5V +5V
Figure 20. MAX244 Pin Configuration and Typical Operating Circuit
