Datasheet
+5V-Powered, Multichannel RS-232
Drivers/Receivers
400kΩ
+10V TO -10V VOLTAGE INVERTER
+5V TO +10V VOLTAGE DOUBLER
V
CC
400kΩ
400kΩ
GND
+5V
+5V
+5V
+5V
+5V
+5V
+5V
18
25
24
23
21
20
1
1μF
1μF
1μF
1μF
15
2
16
3
17
5kΩ
5kΩ
5kΩ
5kΩ
5kΩ
5kΩ
5kΩ
5kΩ
5kΩ
5kΩ
ENTA
C2-
C2+
C1-
C1+
TA1OUT
TA1IN
TA2OUT
TA2IN
TA3OUT
TA3IN
8 RA1IN
10 RA1OUT
7 RA2IN
11 RA2OUT
6 RA3IN
12 RA3OUT
5 RA4IN
13 RA4OUT
4 RA5IN
14
19
RA5OUT
9
27
26
22
44
30
43
29
42
28
37
35
38
34
39
33
40
32
41
31
36ENRA
ENTB
V-
V+
TB1OUT
TB1IN
TB2OUT
TB2IN
TB3OUT
TB3IN
RB1IN
RB1OUT
RB2IN
RB2OUT
RB3IN
RB3OUT
RB4IN
RB4OUT
RB5IN
RB5OUT
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
RA4IN
RA5IN
MAX249
PLCC
TOP VIEW
TA3OUT
TA2OUT
TA1OUT
TB1OUT
TB2OUT
TB3OUT
RB4IN
RB5IN
GND
V+
C1+
C2+
C1-
V-
C2-
TB3IN
ENTB
RB2IN
RB1IN
RB1OUT
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)
RB2OUT
RB3OUT
RB4OUT
RB5OUT
TB1IN
TB2INTA3IN
TA2IN
TA1IN
RA4OUT
RA5OUT
RA3OUT
RA2OUT
RA1OUT
ENRA
RA1IN
7
39
RB3IN
RA2IN
6
18
RA3IN
ENRB
ENTA
1μF
+
Figure 25. MAX249 Pin Configuration and Typical Operating Circuit
34
Maxim Integrated
MAX220–MAX249
MAX220–MAX249