MAX220–MAX249
+5V-Powered, Multichannel RS-232
Drivers/Receivers
+5V
1μF
TOP VIEW
1μF
20
21
V
22
C1+
C1-
CC
1μF
1μF
23
24
V+
V-
+5V TO +10V VOLTAGE DOUBLER
26
C2+
C2-
1μF
25
+10V TO -10V VOLTAGE INVERTER
43
42 41 40
6
5
4
3
2
1
44
+5V
+5V
+5V
+5V
2 TA1OUT
TB1OUT 44
+
400kΩ
400kΩ
15 TA1IN
2 TA2OUT
TB1IN 30
RA3IN
7
8
9
39 RB4IN
38 RB3IN
37 RB2IN
36 RB1IN
35 RB1OUT
34 RB2OUT
33 RB3OUT
32 RB4OUT
31 RB5OUT
30 TB1IN
RA2IN
RA1IN
TB2OUT 43
RA1OUT 10
RA2OUT 11
RA3OUT 12
RA4OUT 13
RA5OUT 14
TA1IN 15
16 TA2IN
3 TA3OUT
TB2IN 29
MAX244
+5V
+5V
+5V
+5V
TB3OUT 42
400kΩ
400kΩ
17 TA3IN
4 TA4OUT
TB3IN 28
TB4OUT 41
TA2IN 16
TA3IN 17
29 TB2IN
18 TA4IN
9 RA1IN
TB4IN 27
RB1IN 36
18 19 20 21 22 23 24 25 26 27 28
5kΩ
5kΩ
PLCC
10 RA1OUT
8 RA2IN
RB1OUT 35
RB2IN 37
5kΩ
5kΩ
MAX249 FUNCTIONAL DESCRIPTION
10 RECEIVERS
11 RA2OUT
7 RA3IN
RB2OUT 34
RB3IN 38
5 A-SIDE RECEIVERS
5 B-SIDE RECEIVERS
8 TRANSMITTERS
5kΩ
5kΩ
4 A-SIDE TRANSMITTERS
4 B-SIDE TRANSMITTERS
NO CONTROL PINS
12 RA3OUT
6 RA4IN
RB3OUT 33
RB4IN 39
5kΩ
5kΩ
13 RA4OUT
5 RA5IN
RB4OUT 32
RB5IN 40
5kΩ
14 RA5OUT
5kΩ
RB5OUT 31
GND
19
ꢁigure 20. MAX244 Pin Configuration and Typical Operating Circuit
Maxim Integrated
29