LTC1544 Linear Technology, LTC1544 Datasheet - Page 9

• Manufacturer Part Number: LTC1544
• Description: Software-Selectable Multiprotocol Transceiver
• Manufacturer: Linear Technology

APPLICATIONS
Mode Selection
The interface protocol is selected using the mode select
pins M0, M1 and M2 (see the Mode Selection table).
For example, if the port is configured as a V.35 interface,
the mode selection pins should be M2 = 1, M1 = 0, M0 = 0.
For the control signals, the drivers and receivers will
operate in V.28 (RS232) electrical mode. For the clock and
data signals, the drivers and receivers will operate in V.35
electrical mode. The DCE/DTE pin will configure the port
for DCE mode when high, and DTE when low.
The interface protocol may be selected simply by plug-
ging the appropriate interface cable into the connector.
The mode pins are routed to the connector and are left
U
LTC1543
LTC1544
INFORMATION
DCE/DTE
DCE/DTE
U
(DATA)
(DATA)
M0
M1
M2
M2
M1
M0
11
12
13
14
14
13
12
11
Figure 10: Single Port DCE V.35 Mode Selection in the Cable
DCE/
W
DTE
22
M2 M1
23
LTC1344A
24
M0 (DATA)
U
1
LATCH
21
CONNECTOR
unconnected (1) or wired to ground (0) in the cable as
shown in Figure 10.
The internal pull-up current sources will ensure a binary 1
when a pin is left unconnected and that the LTC1543/
LTC1544 and the LTC1344A enter the no-cable mode
when the cable is removed. In the no-cable mode the
LTC1543/LTC1544 supply current drops to less than
200 A and all LTC1543/LTC1544 driver outputs and
LTC1344A resistive terminations are forced into a high
impedance state.
The mode selection may also be accomplished by using
jumpers to connect the mode pins to ground or V
NC
NC
1544 F10
CABLE
LTC1544
CC
.
9