LTC1544_15 Datasheet, PDF (8/20 Pages) Linear Technology – Software-Selectable Multiprotocol Transceiver

LTC1544
APPLICATIONS INFORMATION
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.
SERIAL
CONTROLLER
TXD
DTE
LTC1543
D1
LTC1344A
LTC1344A
TXD
103Ω
DCE
LTC1543
R3
SERIAL
CONTROLLER
TXD
SCTE
D2
SCTE
103Ω
R2
SCTE
D3
R1
TXC
R1
RXC
R2
RXD
R3
103Ω
TXC
103Ω
RXC
103Ω
RXD
D3
TXC
D2
RXC
D1
RXD
RTS
DTR
DCD
DSR
CTS
LL
8
LTC1544
D1
RTS
D2
DTR
D3
R1
DCD
R2
DSR
R3
CTS
LL
D4
R4
LTC1544
R3
R2
R1
D3
D2
D1
R4
D4
Figure 9. Complete Multiprotocol Interface in EIA530 Mode
RTS
DTR
DCD
DSR
CTS
LL
1544 F09