Datasheet

8
LTC1544
Overview
The LTC1543/LTC1544 form the core of a complete soft-
ware-selectable DTE or DCE interface port that supports
the RS232, RS449, EIA530, EIA530-A, V.35, V.36 or X.21
protocols. Cable termination may be implemented using
the LTC1344A software-selectable cable termination chip
or by using existing discrete designs.
A complete DCE-to-DTE interface operating in EIA530
mode is shown in Figure 9. The LTC1543 of each port is
used to generate the clock and data signals. The LTC1544
is used to generate the control signals along with LL (Local
Loop-back).The LTC1344A cable termination chip is used
only for the clock and data signals because they must
support V.35 cable termination. The control signals do not
need any external resistors.
Figure 9. Complete Multiprotocol Interface in EIA530 Mode
LTC1543
DCEDTE
LTC1543
LTC1344A
LTC1344A
1544 F09
D3
D3
R1
103Ω
103Ω
103Ω
R3
LTC1544
D4
R1
R2
R3
LL
TXC
RXC
RXD
TXD
SCTE
TXC
RXC
RXD
SERIAL
CONTROLLER
D2
103Ω
SCTE
R2
D1
103Ω
TXD
R3
R1
D2
D1
LTC1544
TXD
SCTE
TXC
RXC
RXD
RTS
DTR
DCD
DSR
CTS
LL
RTS
DTR
DCD
DSR
CTS
RTS
DTR
DCD
DSR
CTS
LL
SERIAL
CONTROLLER
R2
R4
R4
D3
D2
D1
R2
R1
R3
D2
D1
D4
D3
APPLICATIONS INFORMATION
WUU
U