LT1039A_01 Datasheet, PDF (5/12 Pages) Linear Technology – Triple RS232 Driver/Receiver with Shutdown

TYPICAL PERFORMANCE CHARACTERISTICS
LT1039A/LT1039A-16
Shutdown to Receiver Output
6V
RECEIVER ^4V
OUTPUT _2V
0V
ON/OFF ^5V
INPUT _0V
V_CC = 5V
2ms/DIV
1039A G11
BIAS Pin Response Time
6V
RECEIVER 1 ^4V
OUTPUT _2V
0V
BIAS INPUT ^5V
(THRU 25kΩ) _0V
V_CC = 5V
0.2µs/DIV
1039A G12
PIN FUNCTIONS (Pin numbers listed are for 18-pin device)
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.
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 the
pins. 0.1µF ceramic capacitors work well.
GND (Pin 10): Ground Pin.
REC IN (Pins 3, 5, 7): Receiver Input Pins. Accepts RS232
voltage levels (±30V) and has 0.4V of hysteresis to pro-
vide 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
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
sharing. 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.
1039afa
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