Datasheet

11
LTC2847
sn2847 2847fs
Figure 17. Complete Multiprotocol Interface in EIA530 Mode
APPLICATIO S I FOR ATIO
WUUU
When the cable is removed, leaving all mode pins uncon-
nected, the LTC2847/LTC2845 will enter no-cable mode.
In this mode the LTC2847/LTC2845 supply current drops
to less than 1000µA and the LTC2847/LTC2845 driver
outputs are forced into a high impedance state. At the
same time, the R2 and R3 receivers of the LTC2847 are
differentially terminated with 103Ω and the other receiv-
ers on the LTC2847 and LTC2845 are terminated with
30kΩ to ground.
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
LTC2847
DCEDTE
LTC2847
2847 F17
D3
R1
103Ω
103Ω
103Ω
R3
LTC2845
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
LTC2845
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
TM
SERIAL
CONTROLLER
R2
D3
R5 D5
D5
R5
RI
RL
TM
RI
RL
TM
RI
RL