LT1039-16 Linear Technology, LT1039-16 Datasheet - Page 6

• Manufacturer Part Number: LT1039-16
• Description: RS232 Driver/Receiver with Shutdown
• Manufacturer: Linear Technology

APPLICATIONS
LT1039/LT1039-16
The driver output stage of the LT1039 offers significantly
improved protection over older bipolar and CMOS de-
signs. In addition to current limiting, the driver output
can be externally forced to 30V with no damage or
excessive current flow, and will not disrupt the supplies.
Some drivers have diodes connected between the out-
puts and the supplies, so externally applied voltages can
cause excessive supply voltage to develop
Placing the LT1039 in the shutdown mode (Pin 17 low)
puts both the driver and receiver outputs in a high imped-
ance state. This allows data line sharing and transceiver
applications.
6
(CHANNEL SELECT)
INPUT A
INPUT B
ON/OFF
Older RS232 Drivers and Other CMOS Drivers
LOGIC
LOGIC
INPUT
LT1039
Sharing a Transmitter Line
U
LT1039 Driver
LT1039 #1
LT1039 #2
DRIVER
DRIVER
INVERTER
INFORMATION
LOGIC
U
EXTERNALLY
OUTPUT CAN
BE FORCED
V
V
+
–
1039 AI03
W
WITH SOME DRIVERS,
EXTERNALLY APPLIED
VOLTAGE CAN FORCE
THE SUPPLIES
RS232
TRANSMISSION
LINE
1039 AI01
U
30V
– 30V
1039 AI02
The shutdown mode also drops all supply currents (V
V
(TRANSMIT/RECEIVE)
TRANSMIT/RECEIVE
+
, V
(CHANNEL SELECT)
–
) to zero for power conscious systems.
ON/OFF
INPUT A
INPUT B
LOGIC
INPUT
ON/OFF
LINE
RS232
RS232
INPUT
Sharing a Receiver Line
LT1039 #1
DRIVER
Transceiver
INVERTER
LT1039 #1
LT1039 #2
RECEIVER
RECEIVER
LOGIC
LT1039 #2
RECEIVER
INVERTER
LOGIC
1039 AI05
1039 AI04
RS232
TRANSMIT/RECEIVE
LINE
LOGIC
OUTPUT
CC
,