
11
LTC1387
U
S
A
O
PPLICATI
WU
U
I FOR ATIO
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
Figure 14. Full-Duplex RS232 (1-Channel), Half-Duplex RS485
RA
RB
DY
DZ
A
B
Y
Z
RA
RB
DY
DZ/SLEW
ON
VCC
RXEN
DXEN
485/232
CONTROLLER
DX
RXEN
DXEN
MODE
INTERFACE
A
B
Y
Z
RS232
RS485
RS232
RS485
RS232
RS485
SHUTDOWN
MODE
RXEN = 1
RXEN = 0
DXEN = 1
DXEN = 0
MODE = 0
MODE = 1
MODE = X
1387 F15
LTC1387
RX
RXD
TXD
Figure 15. Full-Duplex RS232 (1-Channel), Full-Duplex RS485/RS422
Figure 16. Full-Duplex RS232 (2-Channel), Full-Duplex RS485/RS422 with SLEW Control
RA
RB
DY
DZ
A
B
Y
Z
RA
RB
DY
DZ/SLEW
ON
RXEN
DXEN
485/232
CONTROLLER
DX1
DX2/SLEW
ON
RXEN
DXEN
MODE
INTERFACE
A
B
Y
Z
RS232
RS485
RS232
RS485
RS232
RS485
SHUTDOWN
MODE
ON = 1
ON = 0
RXEN = 1
RXEN = 0
DXEN = 1
DXEN = 0
MODE = 0
MODE = 1
MODE = X
1387 F16
LTC1387
RX1
RX2
RXD
RS232
CTS
TXD
RS232
RTS
RA
RB
DY
DZ
A
B
Y
Z
RA
RB
DY
DZ/SLEW
ON
VCC
RXEN
DXEN
485/232
CONTROLLER
DX
RXEN
DXEN
MODE
INTERFACE
A
B
RS232
RS485
RS232
RS485
SHUTDOWN
MODE
TRANSMIT MODE
RECEIVE MODE
MODE
RXEN = 1
RXEN = 0
RXEN = 1
RXEN = 0
DXEN = 0
DXEN = 1
DXEN = 0
MODE = 0
MODE = 1
MODE = 0
1387 F14
LTC1387
RX
TXD
RXD