LTC1344
Software-Selectable
Cable Terminator
FEATURES
s
DESCRIPTIO
s
Software-Selectable Cable Termination for:
RS232 (V.28)
RS423 (V.10)
RS422 (V.11)
RS485
RS449
EIA530
EIA530-A
V.35
V.36
X.21
Outputs Won’t Load the Line with Power Off
The LTC
®
1344 features six software-selectable
multiprotocol cable terminators. Each terminator can be
configured as an RS422 (V.11) 100Ω minimum differen-
tial load, V.35 T-network load or an open circuit for use
with RS232 (V.28) or RS423 (V.10) transceivers that
provide their own termination. When combined with the
LTC1343, the LTC1344 forms a complete software-select-
able multiprotocol serial port. A data bus latch feature
allows sharing of the select lines between multiple inter-
face ports.
The LTC1344 is available in a 24-lead SSOP.
, LTC and LT are registered trademarks of Linear Technology Corporation.
APPLICATIO S
s
s
s
Data Networking
CSU and DSU
Data Routers
TYPICAL APPLICATION
CTS
DSR
DCD
DTR
RTS
RL
TM
RXD
RXC
TXC
SCTE
TXD
LL
Daisy-Chained Control Outputs
LTC1343
D4
R4
R3
R2
R1
D3
D2
D1
R4
R3
R2
R1
LTC1343
D4
D3
D2
D1
13 5
22 6
10 8
23 20 19
4
21
1
7
25
16 3
9
17 12 15
11 24 14 2
DB-25 CONNECTOR
U
LTC1344
18
U
U
DSR B
DSR A (107)
RL A (140)
CTS B
CTS A (106)
DTR B
DTR A (108)
RTS B
RTS A (105)
SHIELD (101)
SGND (102)
TM A (142)
RXD B
RXD A (104)
RXC B
RXC A (115)
DCD B
DCD A (109)
SCTE B
SCTE A (113)
TXD B
TXD A (103)
LL A (141)
TXC B
TXC A (114)
1344 TA01
1
LINER [ LINEAR TECHNOLOGY ]
