Datasheet

12
LTC2846
sn2846 2846fs
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 LTC2846/LTC2844 will enter no-cable mode.
In this mode the LTC2846/LTC2844 supply current drops
to less than 900µA and the LTC2846/LTC2844 driver out-
puts are forced into a high impedance state. At the same
time, the R2 and R3 receivers of the LTC2846 are differ-
entially terminated with 103 and the other receivers on
the LTC2846 and LTC2844 are terminated with 30k 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
LTC2846
DCEDTE
LTC2846
2846 F17
D3
R1
103
103
103
R3
LTC2844
D3
D4 R4
D2
R1
R4
R2
R3
LL
TXC
RXC
RXD
TXD
SCTE
TXC
RXC
RXD
SERIAL
CONTROLLER
D2
103
SCTE
R2
D1
103
TXD
R3
R1
D2
D1
LTC2844
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