Datasheet

10
LTC2844
sn2844 2844fs
Overview
The LTC2846/LTC2844 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.
A complete DCE-to-DTE interface operating in EIA530
mode is shown in Figure 9. The LTC2846 of each port is
used to generate the clock and data signals. The LTC2844
is used to generate the control signals along with LL (local
loop-back). Cable termination is used only for the clock
and data signals. The control signals do not need any
external resistors.
Figure 9. Complete Multiprotocol Interface in EIA530 Mode
APPLICATIONS INFORMATION
WUU
U
LTC2846
DCEDTE
LTC2846
D3
R1
103Ω
103Ω
103Ω
R3
TXD
SCTE
TXC
RXC
RXD
103Ω
R2
103Ω
R3
R1
D2
D1
R2
D3
2844 F09
LTC2844
D4
R1
R2
R3
LL
TXC
RXC
RXD
SERIAL
CONTROLLER
SCTE
TXD
LTC2844
TXD
SCTE
TXC
RXC
RXD
RTS
DTR
DCD
DSR
CTS
LL
RTS
DTR
DCD
DSR
CTS
RTS
DTR
DCD
DSR
CTS
LL
SERIAL
CONTROLLER
R4
R4
D3
D2
D1
R2
R1
R3
D2
D1
D4
D3
D2
D1