
+5V-Powered, Multichannel RS-232
Drivers/Receivers
GND
3
18
R3OUT
12
R4OUT
R3IN
R4IN
5k
Ω
5k
Ω
22
21
R2OUT
R2IN
5k
Ω
RS-232
OUTPUTS
TTL/CMOS
INPUTS
RS-232
INPUTS
TTL/CMOS
OUTPUTS
R2
1
2
R1OUT
R1IN
5k
Ω
R1
R3
R4
10
9
R5OUT
R5IN
5k
Ω
R5
19
24 T1IN
T1OUT
+5V
400k
Ω
+5V
23
20
T2IN
T2OUT
T2
400k
Ω
16
T3OUT
13
T3IN
+5V
T3
400k
Ω
C1+
C1-
1.0
μF
6
VCC
8
+5V INPUT
4
5
1.0
μF
+10V TO -10V
VOLTAGE INVERTER
17
1.0
μF
T1
24
23
22
21
20
19
18
17
1
2
3
4
5
6
7
8
T1IN
T2IN
R2OUT
R2IN
VCC
GND
R1IN
R1OUT
T1OUT
R3IN
R3OUT
V-
C-
C+
V+
16
15
14
13
9
10
11
12
T3IN
N.C.
EN
T3OUT
R4IN
R4OUT
R5OUT
R5IN
DIP/SO
MAX239
T2OUT
+7.5V TO +13.2V
INPUT
7
V+
11
EN
14
15
N.C.
V-
+
TOP VIEW
Figure 17. MAX239 Pin Configuration and Typical Operating Circuit
26
Maxim Integrated
MAX220–MAX249