Datasheet

10
LTC1546
Figure 17. Complete Multiprotocol Interface in EIA530 Mode
LTC1546
DCEDTE
LTC1546
1546 F17
D3
R1
103Ω
103Ω
103Ω
R3
LTC1544
D3
D4 R4
D2
R1
R4
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
D3
R2
R1
D1
R3
D2
D1
D4
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
D3
Cable Termination
Traditional implementations used expensive relays to
switch resistors or required the user to change termina-
tion modules every time a new interface standard was
selected. Switching the terminations with FETs is difficult
because the FETs must remain off when the signal voltage
is beyond the supply voltage. Alternatively, custom cables
may contain termination in the cable head or route signals
to various terminations on the board.
The LTC1546/LTC1544 chipset solves the cable termina-
tion switching problem by automatically providing the
appropriate termination and switching on-chip for the
V.10 (RS423), V.11 (RS422), V.28 (RS232) and V.35
electrical protocols.
APPLICATIO S I FOR ATIO
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