LT1281ACSW Linear Technology, LT1281ACSW Datasheet - Page 5

• Manufacturer Part Number: LT1281ACSW
• Description: IC DRVR/RCVR 5V RS232 DUAL16SOIC
• Manufacturer: Linear Technology
• Type: Transceiverr

Specifications of LT1281ACSW

• Number Of Drivers/receivers: 2/2
• Protocol: RS232
• Voltage - Supply: 4.5 V ~ 5.5 V
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (0.300", 7.5mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: LT1281ACS

TYPICAL PERFOR
PI FU CTIO S
V
with a 0.1 F ceramic capacitor close to the package pin.
Insufficient supply bypassing can result in low output
drive levels and erratic charge pump operation.
GND: Ground Pin.
ON/OFF: A TTL/CMOS Compatible Operating Mode Con-
trol. A logic low puts the LT1280A in shutdown mode.
Supply current drops to zero and both driver and receiver
outputs assume a high impedance state. A logic high fully
enables the device.
V
1.5V. This pin requires an external charge storage capaci-
tor C 0.1 F, tied to ground or V
tors may be used to reduce supply ripple. With multiple
transceivers, the V
common capacitors.
V
(2V
capacitor C 0.1 F. Larger value capacitors may be used
to reduce supply ripple. With multiple transceivers, the V
and V
TR1 IN, TR2 IN: RS232 Driver Input Pins. These inputs are
TTL/CMOS compatible. Inputs should not be allowed to
float. Tie unused inputs to V
TR1 OUT, TR2 OUT: Driver Outputs at RS232 Voltage
Levels. Driver output swing meets RS232 levels for loads
up to 3k. Slew rates are controlled for lightly loaded lines.
CC
+
–
: Positive Supply Output (RS232 Drivers). V
: Negative Supply Output (RS232 Drivers). V
U
CC
: 5V Input Supply Pin. This pin should be decoupled
ON/OFF PIN
DRIVER 1
DRIVER 2
–
– 2.5V). This pin requires an external charge storage
OUTPUT
OUTPUT
pins may be paralleled into common capacitors.
U
– 10V
GND
GND
– 5V
10V
5V
Shutdown to Driver Outputs
+
and V
U
–
W
CC
pins may be paralleled into
.
A
CC
U
. Larger value capaci-
CE
C
LT1280A • TPC12
HARA TERISTICS
+
2V
–
C
CC
–
–
+
DRIVER OUTPUT
DRIVER OUTPUT
Output current capability is sufficient for load conditions
up to 2500pF. Outputs are in a high impedance state when
in shutdown mode or V
circuit protected from V
higher voltages will not damage the device if the overdrive
is moderately current limited. Short circuits on one
output can load the power supply generator and may
disrupt the signal levels of the other outputs. The driver
outputs are protected against ESD to 10kV for human
body model discharges.
REC1 IN, REC2 IN: Receiver Inputs. These pins accept
RS232 level signals ( 30V) into a protected 5k terminat-
ing resistor. The receiver inputs are protected against ESD
to 10kV for human body model discharges. Each receiver
provides 0.4V of hysteresis for noise immunity. Open
receiver inputs assume a logic low state.
REC1 OUT, REC2 OUT: Receiver outputs with TTL/CMOS
Voltage Levels. Outputs are in a high impedance state
when in shutdown mode to allow data line sharing. Out-
puts are fully short-circuit protected to ground or V
the power ON, OFF or in the shutdown mode.
C1
These pins require two external capacitors C 0.1 F: one
from C1
be deleted if a separate 12V supply is available and
connected to pin C1
separate – 12V supply is connected to pin V
C
+
L
, C1
= 2500pF
R
R
INPUT
L
L
= 3k
= 3k
+
–
to C1
, C2
Driver Output Waveforms
+
–
, C2
and another from C2
+
–
. Similarly, C2 should be deleted if a
: Commutating Capacitor Inputs.
CC
LT1280A/LT1281A
–
+ 30V to V
= 0V. Outputs are fully short-
LT1280A • TPC13
+
+
to C2
– 30V. Applying
–
–
.
. C1 should
CC
with
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