Datasheet

LT1039A/LT1039A-16
5
1039afb
For more information www.linear.com/1039
Typical perForMance characTerisTics
Shutdown to Driver Output Shutdown to Receiver Output
BIAS Pin Response Time
2µs/DIV
RECEIVER
OUTPUT
10V
5V
0V
0V
5V
0V
–10V
–5V
DRIVER
OUTPUT
OUTPUT
HIGH
OUTPUT
LOW
ON/OFF
INPUT
1039A G10
V
+
= 12V
V
–
= –12V
R
L
= 3k
2ms/DIV
RECEIVER
OUTPUT
6V
4V
2V
0V
0V
5V
ON/OFF
INPUT
1039A G11
V
CC
= 5V
0.2µs/DIV
RECEIVER 1
OUTPUT
6V
4V
2V
0V
5V
0V
BIAS INPUT
(THRU 25kΩ)
1039A G12
V
CC
= 5V
pin FuncTions
V
+
, V
–
(Pins 1, 9): Driver Supply Pins. Supply current
drops to zero in shutdown mode. Driver outputs are in a
high impedance state when V
+
and V
–
= 0V.
BIAS (Pin 2): Keeps receiver 1 on while the LT1309A is
in the shutdown mode. Leave BIAS pin open when not in
use. See Applications Information for proper use.
REC IN (Pins 3, 5, 7): Receiver Input Pins. Accepts
RS232 voltage levels (±30V) and has 0.4V of hysteresis
to provide noise immunity. Input impedance is nominally
30kΩ. Receiver input pins are internally protected from
ESD transients. In order to insure proper functioning of
the ESD protection devices, the V
CC
and V
–
supply pins
must be bypassed with low ESR capacitors located close
to the pins. A 0.1µF ceramic capacitor works well.
TR OUT (Pins 4, 6, 8): Driver Outputs with RS232 Voltage
Levels. Outputs are in a high impedance state when in the
shutdown mode or when power is off (V
+
and V
–
= 0V)
to allow data line sharing. Outputs are fully short-circuit
protected from V
–
+ 30V to V
+
– 30V with power on, off
or in the shutdown mode. Typical output breakdowns are
greater than ±45V and higher applied voltages
will not
damage the device if moderately current limited. Driver
-
output pins are internally protected from ESD transients.
In order to insure proper functioning of the ESD protec-
tion devices, the V
+
and V
–
supply pins must be bypassed
with low ESR capacitors located close to thepins. 0.1µF
ceramic capacitors work well.
GND (Pin 10): Ground Pin.
TR IN (Pins 11, 13, 15): RS232 Driver Input Pins. Inputs
are TTL/CMOS compatible. Inputs should not be allowed
to float. Tie unused inputs to V
CC
.
REC OUT (Pins 12, 14, 16): Receiver Outputs with TTL/
CMOS Voltage Levels. Outputs are in a high impedance
state when in the shutdown mode to allow data line shar
-
ing. Outputs are fully short-circuit protected to ground or
V
CC
with power on, off or in the shutdown mode.
ON/OFF (Pin 17): Controls the operation mode of the
LT1039A and is TTL/CMOS compatible. A logic low puts
the device in the shutdown mode which reduces input
supply current to zero and places both driver and receiver
outputs in a high impedance state.
V
CC
(Pin 18): 5V Power for Receivers.
(Pin numbers listed are for 18-pin device)