LT1081 LINER [Linear Technology], LT1081 Datasheet - Page 7

• Manufacturer Part Number: LT1081
• Description: Advanced Low Power 5V RS232 Dual Driver/Receiver
• Manufacturer: LINER [Linear Technology]

APPLICATIO S I FOR ATIO
When driving CMOS logic from a receiver that will be used
in the SHUTDOWN mode and there is no other active
receiver on the line, a 51k resistor can be placed from the
logic input to V
receiver output is in a high impedance state.
To protect against receiver input overloads in excess of
still maintain RS232 compatibility.
TYPICAL APPLICATIO
30V, a voltage clamp can be placed on the data line and
RS232
* A PTC THERMISTOR WILL ALLOW
CONTINUOUS OVERLOAD OF GREATER THAN 100V
INPUT
ON/OFF
RS232
* FORCES LOGIC INPUT STATE WHEN V
INPUT
INPUT
1k*
CC
to force a definite logic level when the
U
LT1080
RECEIVER
30V
30V
U
5k
51k*
OUTPUTS
ON/OFF
12V INPUT*
RECEIVER
U
INPUTS
W
LOGIC
LOGIC
V
ON/OFF
CC
CMOS
LOGIC
IS LOW
1 F
1080/81 F06
* PIN 1 USED ON LT1081.
LOGIC
OUTPUT
LOGIC
OUTPUT
1080/81 F067
12
11
13
10
18
U
2
4
5
6
Operating with 5V and 12V
LT1080
5k
5k
The generated driver supplies (V
power external circuitry such as other RS232 drivers or op
amps. They should be loaded with care, since excessive
loading can cause the generated supply voltages to drop,
causing the RS232 driver output voltages to fall below
RS232 requirements. See the graph “Supply Generator
Outputs” for a comparison of generated supply voltage
versus supply current.
17
3
7
15
8
14
9
16
+
1 F
1 F
1080/81 • TA03
16
5V INPUT
–12V OUTPUT
RS232 OUTPUT
RS232 OUTPUT
RS232 INPUT
RS232 INPUT
GND
LT1080
3
V
V
7
+
–
DRIVER
1 F
LT1080/LT1081
+
and V
EXTERNAL OP AMP
+
–
–
) may be used to
V
V
+
–
1080/81 F08
7