LTC1345
U
W U U
APPLICATIONS INFORMATION
RS422/RS485 Applications
5
0
RECEIVER
OUTPUT
5V/DIV
The receivers on the LTC1345 are ideal for RS422 and
RS485 applications. Using the test circuit in Figure 9, the
LTC1345 receivers are able to successfully reconstruct
the data stream with the common-mode voltage meeting
RS422 and RS485 requirements (12V to –7V).
0V
–5V
RECEIVER
A
B
Figures 10 and 11 show that the LTC1345 receivers are
verycapableofreconstructingdataatratesupto10Mbaud.
INPUT
–10V
5V/DIV
V
V
CC2
5V
CC1
LTC1345 • F10
5V
Figure 10. –7V Common Mode
A
BX
TTL
OUT
LTC485
100Ω
100Ω LTC1345
B
AX
RECEIVER
B
GND
GND
15V
10V
5V
INPUT
A
+
–
TTL
IN
5V/DIV
12V TO –7V
COMMON-MODE VOLTAGE
LTC1345 • F09
Figure 9 RS422/RS485 Receiver Interface
0V
5
0
RECEIVER
OUTPUT
5V/DIV
LTC1345 • F11
Figure 11. 12V Common Mode
10
Linear [ Linear ]
