Datasheet

MAX220–MAX249
+5V-Powered, Multichannel RS-232
Drivers/Receivers
30 ______________________________________________________________________________________
400k
Ω
V
CC
400k
Ω
400k
Ω
GND
+5V
+5V
+5V
+5V
+5V
40
17
1
μ
F
3
18
4
19
5
5k
Ω
5k
Ω
5k
Ω
5k
Ω
5k
Ω
5k
Ω
5k
Ω
5k
Ω
5k
Ω
5k
Ω
T
A2
OUT
T
A2
IN
T
A3
OUT
T
A3
IN
T
A4
OUT
T
A4
IN
1
11 R
A1
IN
10 R
A1
OUT
12 R
A2
IN
9R
A2
OUT
13 R
A3
IN
8R
A3
OUT
14 R
A4
IN
7R
A4
OUT
15 R
A5
IN
6
20
R
A5
OUT
23
37
22
36
21
35
29
30
28
31
27
32
26
33
25
34
T
B2
OUT
T
B2
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
+5V
+5V
400k
Ω
16
2
T
A1
OUT
T
A1
IN
24
38
T
B1
OUT
T
B1
IN
+5V
+5V
40 V
CC
ENT
T
B1
IN
T
B2
IN
T
B3
IN
T
B4
IN
R
B5
OUT
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
ENR
T
A1
IN
T
A2
IN
T
A3
IN
T
A4
IN
R
A5
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
R
A5
IN
T
A1
OUT
T
A2
OUT
T
A3
OUT
T
A4
OUT
GND
TOP VIEW
MAX245
30
29
28
27
26
25
24
23
22
21
11
12
13
14
15
16
17
18
19
DIP
20
MAX245 FUNCTIONAL DESCRIPTION
10 RECEIVERS
5 A-SIDE RECEIVERS (R
A5
ALWAYS ACTIVE)
5 B-SIDE RECEIVERS (R
B5
ALWAYS ACTIVE)
8 TRANSMITTTERS
4 A-SIDE TRANSMITTERS
2 CONTROL PINS
1 RECEIVER ENABLE (ENR)
1 TRANSMITTER ENABLE (ENT)
39
ENR
ENT
Figure 21. MAX245 Pin Configuration and Typical Operating Circuit