Datasheet

10
LTC1345
APPLICATIONS INFORMATION
WUU
U
RS422/RS485 Applications
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).
Figures 10 and 11 show that the LTC1345 receivers are
very capable of reconstructing data at rates up to 10Mbaud.
Figure 10. –7V Common Mode
LTC1345 • F10
RECEIVER
OUTPUT
5V/DIV
B
A
–10V
–5V
0V
0
5
Figure 11. 12V Common Mode
RECEIVER
OUTPUT
5V/DIV
15V
5
0
LTC1345 • F11
10V
5V
0V
RECEIVER
INPUT
5V/DIV
B
A
RECEIVER
INPUT
5V/DIV
LTC485
12V TO –7V
COMMON-MODE VOLTAGE
V
CC1
5V
100Ω
100Ω
ABX
B
AX
GND
LTC1345 • F09
LTC1345
V
CC2
5V
GND
TTL
IN
TTL
OUT
–
+
Figure 9 RS422/RS485 Receiver Interface