16
LTC1321/LTC1322/LTC1335
U
SA
O
PP
L
IC
AT
ITY
P
I
CA
L
A typical EIA562/RS232 interface application is shown in
Figure 17 with LTC1322. A typical EIA562 interface appli-
cation with LTC1335 is shown in Figure 18.
A typical connection for RS485 transceiver is shown in
Figure 19. A twisted pair of wires connects up to 32 drivers
and receivers for half duplex multi-point data transmis-
sion. The wires must be terminated at both ends with
resistors equal to the wire’s characteristic impedance,
generally 120Ω. An optional shield around the twisted pair
helps to reduce unwanted noise and should be connected
to ground at one end.
1/2 LTC1322 1/2 LTC1322
1321/22/35 F17
17
16
15
14
7
DR IN
DR IN
RX OUT
RX OUT
OV
3
2
5
4
8
9
10
11
22
23
20
21
6
RX OUT
RX OUT
DR IN
DR IN
0V
EIA562/
RS232
INTERFACE
LINES
Figure 17. Typical Connection for EIA562/RS232 Interface
Figure 18. Typical Connection for EIA562 Interface
1/2 LTC1335 1/2 LTC1335
1321/22/35 F18
17
16
15
14
7
DR IN
DR IN
RX OUT
RX OUT
OV
3
2
5
4
8
9
10
11
22
23
20
21
6
RX OUT
RX OUT
DR IN
DR IN
0V
EIA562
INTERFACE
LINES
1
OE = 0V
1
OE = 0V
Figure 19. Typical Connection for RS485 Interface
5V
2
1/2 LTC1322/LTC1335
1/2 LTC1322/LTC1335
1/2 LTC1322/LTC1335
1321/22/35 F19
RX OUT
DR ENABLE
DR IN
5V
120Ω
3
4
5
22
21
20
6
11
10
9
8
7
RX OUT
16
5V
DR ENABLE
54 32
20
DR IN RX OUT
DR ENABLE
21 22 6
15
DR IN
17
120Ω
