MAX220–MAX249
+5V-Powered, Multichannel RS-232
Drivers/Receivers
TOP VIEW
+5V
1μF
1μF
20
21
C1+
C1-
V
22
CC
V+
V-
1μF
1μF
23
24
+5V TO +10V VOLTAGE DOUBLER
26
C2+
C2-
1μF
43
42 41 40
6
5
4
3
2
1
44
25
+10V TO -10V VOLTAGE INVERTER
18 ENTA
ENTB 27
+
+5V
+5V
+5V
1 TA1OUT
TB1OUT 44
RA2IN
7
8
9
39 RB3IN
38 RB2IN
37 RB1IN
36 ENRB
400kΩ
RA1IN
ENRA
14 TA1IN
2 TA2OUT
15 TA2IN
3 TA3OUT
16 TA3IN
4 TA4OUT
17 TA4IN
TB1IN 31
TB2OUT 43
TB2IN 30
+5V
RA1OUT 10
RA2OUT 11
RA3OUT 12
RA4OUT 13
TA1IN 14
400kΩ
35 RB1OUT
34 RB2OUT
33 RB3OUT
32 RB4OUT
31 TB1IN
30 TB2IN
29 TB3IN
MAX248
+5V
+5V
TB3OUT 42
TB3IN 29
400kΩ
TA2IN 15
TA3IN 16
+5V
400kΩ
+5V
TA4IN 17
TB4OUT 41
TB4IN 28
18 19 20 21 22 23 24 25 26 27 28
8 RA1IN
RB1IN 37
PLCC
5kΩ
5kΩ
10 RA1OUT
7 RA2IN
RB1OUT 35
RB2IN 38
MAX248 FUNCTIONAL DESCRIPTION
8 RECEIVERS
4 A-SIDE RECEIVERS
5kΩ
5kΩ
4 B-SIDE RECEIVERS
8 TRANSMITTERS
11 RA2OUT
6 RA3IN
RB2OUT 34
RB3IN 39
4 A-SIDE TRANSMITTERS
4 B-SIDE TRANSMITTERS
4 CONTROL PINS
5kΩ
5kΩ
ENABLE RECEIVER A-SIDE (ENRA)
ENABLE RECEIVER B-SIDE (ENRB)
ENABLE RECEIVER A-SIDE (ENTA)
ENABLE RECEIVER B-SIDE (ENTB)
12 RA3OUT
5 RA4IN
RB3OUT 33
RB4IN 40
5kΩ
5kΩ
13 RA4OUT
9 ENRA
RB4OUT 32
ENRB 36
GND
19
ꢁigure 24. MAX248 Pin Configuration and Typical Operating Circuit
Maxim Integrated
33
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
