Datasheet

MAX220–MAX249
+5V-Powered, Multichannel RS-232
Drivers/Receivers
34 ______________________________________________________________________________________
400k
Ω
+10V TO -10V VOLTAGE INVERTER
+5V TO +10V VOLTAGE DOUBLER
V
CC
400k
Ω
400k
Ω
GND
+5V
+5V
+5V
+5V
+5V
+5V
+5V
18
25
24
23
21
20
1
1
μ
F
1
μ
F
1
μ
F
1
μ
F
15
2
16
3
17
5k
Ω
5k
Ω
5k
Ω
5k
Ω
5k
Ω
5k
Ω
5k
Ω
5k
Ω
5k
Ω
5k
Ω
ENTA
C2-
C2+
C1-
C1+
T
A1
OUT
T
A1
IN
T
A2
OUT
T
A2
IN
T
A3
OUT
T
A3
IN
8R
A1
IN
10 R
A1
OUT
7R
A2
IN
11 R
A2
OUT
6R
A3
IN
12 R
A3
OUT
5R
A4
IN
13 R
A4
OUT
4R
A5
IN
14
19
R
A5
OUT
9
27
26
22
44
30
43
29
42
28
37
35
38
34
39
33
40
32
41
31
36ENRA
ENTB
V-
V+
T
B1
OUT
T
B1
IN
T
B2
OUT
T
B2
IN
T
B3
OUT
T
B3
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
ENRB
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
V
CC
R
A4
IN
R
A5
IN
MAX249
PLCC
TOP VIEW
T
A3
OUT
T
A2
OUT
T
A1
OUT
T
B1
OUT
T
B2
OUT
T
B3
OUT
R
B4
IN
R
B5
IN
GND
V+
C1+ C2+
C1-
V-
C2-
T
B3
IN
ENTB
R
B2
IN
R
B1
IN
R
B1
OUT
MAX249 FUNCTIONAL DESCRIPTION
10 RECEIVERS
5 A-SIDE RECEIVERS
5 B-SIDE RECEIVERS
6 TRANSMITTERS
3 A-SIDE TRANSMITTERS
3 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)
R
B2
OUT
R
B3
OUT
R
B4
OUT
R
B5
OUT
T
B1
IN
T
B2
INT
A3
IN
T
A2
IN
T
A1
IN
R
A4
OUT
R
A5
OUT
R
A3
OUT
R
A2
OUT
R
A1
OUT
ENRA
R
A1
IN
7
39
R
B3
IN
R
A2
IN
6
18
R
A3
IN
ENRB
ENTA
1
μ
F
Figure 25. MAX249 Pin Configuration and Typical Operating Circuit