1
LT1280A/LT1281A
Low Power 5V RS232
Dual Driver/Receiver with
0.1µF Capacitors
R
Output Waveforms
LT1280A • TA02
DRIVER
OUTPUT
R
L
= 3k
C
L
= 2500pF
RECEIVER
OUTPUT
C
L
= 50pF
INPUT
S
FEATURE
D
U
ESCRIPTIO
The LT
®
1280A/LT1281A are dual RS232 driver/receiver
pairs with integral charge pump to generate RS232 volt-
age levels from a single 5V supply. These circuits feature
rugged bipolar design to provide operating fault tolerance
and ESD protection unmatched by competing CMOS
designs. Using only 0.1µF external capacitors, these cir-
cuits consume only 40mW of power, and can operate to
120kbaud even while driving heavy capacitive loads. New
ESD structures on the chip allow the LT1280A/LT1281A to
survive multiple ±10kV strikes, eliminating the need for
costly TransZorbs
®
on the RS232 line pins. The LT1280A/
LT1281A are fully compliant with EIA RS232 standards.
Driver outputs are protected from overload, and can be
shorted to ground or up to ±30V without damage. During
shutdown or power-off conditions, driver and receiver
outputs are in a high impedance state, allowing line
sharing.
The LT1281A is available in 16-pin DIP and SO packages.
The LT1280A is supplied in 18-pin DIP and SO packages
for applications which require shutdown.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TransZorb is a registered trademark of General Instruments, GSI
■
Portable Computers
■
Battery-Powered Systems
■
Power Supply Generator
■
Terminals
■
Modems
U
S
A
O
PPLICATI
U
A
O
PPLICATITYPICAL
5k
5k
0.1µF
0.1µF
0.1µF
0.1µF
LOGIC
INPUTS
LOGIC
OUTPUTS
ON/OFF 18
10
13
11
12
6
5
4
2
16
9
14
8
15
7
3
17 5V INPUT
V
+
OUT
V
–
OUT
RS232 OUTPUT
RS232 OUTPUT
RS232 INPUT
RS232 INPUT
LT1280A • TA01
LT1280A
+
+
+
+
■
10mA Max Supply Current
■
ESD Protection over ±10kV
■
Uses Small Capacitors: 0.1µF
■
120kBaud Operation for R
L
= 3k, C
L
= 2500pF
■
250kBaud Operation for R
L
= 3k, C
L
= 1000pF
■
Outputs Withstand ±30V Without Damage
■
CMOS Comparable Low Power: 40mW
■
Operates from a Single 5V Supply
■
Rugged Bipolar Design
■
Outputs Assume a High Impedance State When Off
or Powered Down
■
Meets All RS232 Specifications
■
Available With or Without Shutdown
■
Absolutely No Latch-up
■
Available in SO Package
2
LT1280A/LT1281A
A
U
G
W
A
W
U
W
ARBSOLUTEXI T
I
S
Supply Voltage (V
CC
) ................................................ 6V
V
+
........................................................................ 13.2V
V
–
...................................................................... –13.2V
Input Voltage
Driver ........................................................... V
–
to V
+
Receiver ............................................... – 30V to 30V
ON/OFF ................................................. –0.3V to 12V
Output Voltage
Driver ...................................... V
+
– 30V to V
–
+ 30V
Receiver .................................... – 0.3V to V
CC
+ 0.3V
Short-Circuit Duration
V
+
................................................................... 30 sec
V
–
................................................................... 30 sec
Driver Output.............................................. Indefinite
Receiver Output.......................................... Indefinite
Operating Temperature Range
LT1280AC/LT1281AC ............................. 0°C to 70°C
LT1280AI/LT1281AI .......................... –40°C to 85°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
WU
U
PACKAGE/ORDER I FOR ATIO
ORDER PART
NUMBER ORDER PART
NUMBER
(Note 2)
ELECTRICAL C CHARA TERISTICS
Consult factory for Military grade parts.
1
2
3
4
5
6
7
8
9
TOP VIEW
18
17
16
15
14
13
12
11
10
NC
C1
+
V
+
C1
–
C2
+
C2
–
V
–
TR2 OUT
REC2 IN
N PACKAGE 18-LEAD PDIP
SW PACKAGE
18-LEAD PLASTIC SO WIDE
ON/OFF
V
CC
GND
TR1 OUT
REC1 IN
REC1 OUT
TR1 IN
TR2 IN
REC2 OUT
T
JMAX
= 125°C, θ
JA
= 80°C/W, θ
JC
= 36°C/W (N)
T
JMAX
= 125°C, θ
JA
= 90°C/ W, θ
JC
= 26°C/W (SW)
LT1280ACN
LT1280AIN
LT1280ACSW
LT1280AISW
1
2
3
4
5
6
7
8
TOP VIEW
16
15
14
13
12
11
10
9
C1
+
V
+
C1
–
C2
+
C2
–
V
–
TR2 OUT
REC2 IN
V
CC
GND
TR1 OUT
REC1 IN
REC1 OUT
TR1 IN
TR2 IN
REC2 OUT
N PACKAGE 16-LEAD PDIP
SW PACKAGE
16-LEAD PLASTIC SO WIDE
T
JMAX
= 125°C, θ
JA
= 90°C/W, θ
JC
= 46°C/W (N)
T
JMAX
= 125°C, θ
JA
= 95°C/W, θ
JC
= 27°C/W (SW)
LT1281ACN
LT1281AIN
LT1281ACSW
LT1281AISW
(Note 1)
PARAMETER CONDITIONS MIN TYP MAX UNITS
Power Supply Generator
V
+
Output 7.9 V
V
–
Output –7.0 V
Supply Current (V
CC
) (Note 3), T
A
= 25°C 8 10 mA
●14 mA
Supply Current When OFF (V
CC
) Shutdown (Note 4) LT1280A Only ●110 µA
Supply Rise Time C1 = C2 = C3 = C4 = 0.1µF 0.2 ms
Shutdown to Turn-On LT1280A Only 0.2 ms
ON/OFF Pin Thresholds Input Low Level (Device Shutdown) ●0.8 1.2 V
Input High Level (Device Enabled) ●1.6 2.4 V
ON/OFF Pin Current 0V ≤ V
ON/OFF
≤ 5V ●–15 80 µA
Oscillator Frequency 130 kHz
Driver
Output Voltage Swing Load = 3k to GND Positive ●5.0 7.5 V
Negative ●–6.3 –5.0 V
Logic Input Voltage Level Input Low Level (V
OUT
= High) ●1.4 0.8 V
Input High Level (V
OUT
= Low) ●2.0 1.4 V
3
LT1280A/LT1281A
Driver Output Voltage
TEMPERATURE (°C)
–55
–10
DRIVER OUTPUT VOLTAGE (V)
–8
–4
–2
0
10
4
050 75
LT1280A • TPC03
–6
6
8
2
–25 25 100 125
OUTPUT HIGH
OUTPUT LOW
R
L
= 3k
V
CC
= 5V
V
CC
= 4.5V
V
CC
= 5.5V
V
CC
= 4.5V
V
CC
= 5V
V
CC
= 5.5V
CCHARA TERISTICS
UW
AT
Y
P
I
CALPER
F
O
RC
E
E
LECTRICAL C CHARA TERISTICS
(Note 2)
PARAMETER CONDITIONS MIN TYP MAX UNITS
Logic Input Current 0.8V ≤ V
IN
≤ 2.0V ●520 µA
Output Short-Circuit Current V
OUT
= 0V ±917 mA
Output Leakage Current Shutdown V
OUT
= ±30V (Note 4) ●10 100 µA
Data Rate (Note 7) R
L
= 3k, C
L
= 2500pF 120 kBaud
R
L
= 3k, C
L
= 1000pF 250 kBaud
Slew Rate R
L
= 3k, C
L
= 51pF 15 30 V/µs
R
L
= 3k, C
L
= 2500pF 4 7 V/µs
Propagation Delay Output Transition t
HL
High-to-Low (Note 5) 0.6 1.3 µs
Output Transition t
LH
Low-to-High 0.5 1.3 µs
Receiver
Input Voltage Thresholds Input Low Threshold (V
OUT
= High) C Grade ●0.8 1.3 V
Input High Threshold (V
OUT
= Low) C Grade ●1.7 2.4 V
Input Low I Grade ●0.2 1.3 V
Input High I Grade ●1.7 3.0 V
Hysteresis ●0.1 0.4 1.0 V
Input Resistance V
IN
= ±10V 357 kΩ
Output Leakage Current Shutdown (Note 4) 0 ≤ V
OUT
≤ V
CC
●110 µA
Output Voltage Output Low, I
OUT
= –1.6mA ●0.2 0.4 V
Output High, I
OUT
= 160µA (V
CC
= 5V) ●3.5 4.2 V
Output Short-Circuit Current Sinking Current, V
OUT
= V
CC
–20 –10 mA
Sourcing Current, V
OUT
= 0V 10 20 mA
Propagation Delay Output Transition t
HL
High-to-Low (Note 6) 250 600 ns
Output Transition t
LH
Low-to-High 350 600 ns
Note 4: Supply current measurements in shutdown are performed with
V
ON/OFF
≤ 0.1V.
Note 5: For driver delay measurements, R
L
= 3k and C
L
= 51pF. Trigger
points are set between the driver’s input logic threshold and the output
transition to the zero crossing (t
HL
= 1.4V to 0V and t
LH
= 1.4V to 0V).
Note 6: For receiver delay measurements, C
L
= 51pF. Trigger points are
set between the receiver’s input logic threshold and the output transition
to standard TTL/CMOS logic threshold (t
HL
= 1.3V to 2.4V and t
LH
= 1.7V
to 0.8V).
Note 7: Data rate operation guaranteed by slew rate, short-circuit current
and propagation delay tests.
The ● denotes specifications which apply over the operating temperature
range (0°C ≤ T
A
≤ 70°C for commercial grade, and –40°C ≤ T
A
≤ 85°C for
industrial grade.
Note 1: Absolute Maximum Ratings are those values beyond which the life
of the device may be impaired.
Note 2: Testing done at V
CC
= 5V and V
ON/OFF
= 3V, unless otherwise
specified.
Note 3: Supply current is measured as the average over several charge
pump cycles. C
+
= C
–
= C1 = C2 = 0.1µF. All outputs are open, with all
driver inputs tied high.
Driver Maximum Output Voltage
vs Load Capacitance
LOAD CAPACITANCE (nF)
0
5.0
PEAK OUTPUT VOLTAGE (V)
5.5
6.0
6.5
7.0
7.5
8.0
2468
LT1280A • TPC01
1013579
20k BAUD
60k BAUD
120k BAUD
Driver Minimum Output Voltage
vs Load Capacitance
LOAD CAPACITANCE (nF)
0
–7.0
PEAK OUTPUT VOLTAGE (V)
–6.5
–6.0
–5.5
–5.0
–4.5
–4.0
2468
LT1280A • TPC02
1013579
120k BAUD
60k BAUD
20k BAUD
4
LT1280A/LT1281A
CCHARA TERISTICS
UW
AT
Y
P
I
CALPER
F
O
RC
E
Receiver Input Thresholds
Driver Leakage in Shutdown
ON/OFF Thresholds
Receiver Short-Circuit Current Slew Rate vs Load Capacitance
TEMPERATURE (°C)
–55
0.50
THRESHOLD VOLTAGE (V)
0.75
1.25
1.50
1.75
3.00
2.25
050 75
LT1280A • TPC04
1.00
2.50
2.75
2.00
–25 25 100 125
INPUT HIGH
INPUT LOW
DATA RATE (kBAUD)
0
0
SUPPLY CURRENT (mA)
10
20
30
40
50
25 50 75 100
LT1280A • TPC05
125 150
2 DRIVERS ACTIVE
R
L
= 3k
C
L
= 2500pF
Supply Current vs Data Rate
TEMPERATURE (°C)
–55
THRESHOLD VOLTAGE (V)
2.0
2.5
3.0
25 75
LT1280A • TPC06
1.5
1.0
–25 0 50 100 125
0.5
0
ON THRESHOLD
OFF THRESHOLD
Supply Current
TEMPERATURE (°C)
–55
0
SUPPLY CURRENT (mA)
10
25
050 75
LT1280A • TPC07
5
20
15
–25 25 100 125
2 DRIVERS LOADED R
L
= 3k
1 DRIVER LOADED R
L
= 3k
NO LOAD
Driver Short-Circuit Current
LOAD CAPACITANCE (nF)
0
SLEW RATE (V/µs)
12
16
4.0
LT1280A • TPC11
8
4
01.0 2.0 3.0 5.0
10
14
6
2
3.5
0.5 1.5 2.5 4.5
+SLEW
–SLEW
TEMPERATURE (°C)
0.1
LEAKAGE CURRENT ( µA)
10
100
LT1280A • TPC08
1
–55 0 50 75
–25 25 100 125
V
OUT
= –30V
V
OUT
= 30V
TEMPERATURE (°C)
–55
SHORT-CIRCUIT CURRENT (mA)
20
25
30
25 75
LT1280A • TPC09
15
10
–25 0 50 100 125
5
0
I
SC+
I
SC–
TEMPERATURE (°C)
–55
0
SHORT-CIRCUIT CURRENT (mA)
20
50
050 75
LT1280A • TPC10
10
40
30
–25 25 100 125
RX I
SC–
RX I
SC+
5
LT1280A/LT1281A
CCHARA TERISTICS
UW
AT
Y
P
I
CALPER
F
O
RC
E
Shutdown to Driver Outputs Driver Output Waveforms
LT1280A • TPC13
LT1280A • TPC12
PI FU CTIO S
U
UU
Output current capability is sufficient for load conditions
up to 2500pF. Outputs are in a high impedance state when
in shutdown mode or V
CC
= 0V. Outputs are fully short-
circuit protected from V
–
+ 30V to V
+
– 30V. Applying
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
CC
with
the power ON, OFF or in the shutdown mode.
C1
+
, C1
–
, C2
+
, C2
–
: Commutating Capacitor Inputs.
These pins require two external capacitors C ≥ 0.1µF: one
from C1
+
to C1
–
and another from C2
+
to C2
–
. C1 should
be deleted if a separate 12V supply is available and
connected to pin C1
+
. Similarly, C2 should be deleted if a
separate –12V supply is connected to pin V
–
.
INPUT
DRIVER OUTPUT
R
L
= 3k
DRIVER OUTPUT
R
L
= 3k
C
L
= 2500pF
10V
5V
GND
DRIVER 1
OUTPUT
DRIVER 2
OUTPUT
ON/OFF PIN
GND
–10V
–5V
V
CC
: 5V Input Supply Pin. This pin should be decoupled
with a 0.1µF 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
+
: Positive Supply Output (RS232 Drivers). V
+
≈ 2V
CC
–
1.5V. This pin requires an external charge storage capaci-
tor C ≥ 0.1µF, tied to ground or V
CC
. Larger value capaci-
tors may be used to reduce supply ripple. With multiple
transceivers, the V
+
and V
–
pins may be paralleled into
common capacitors.
V
–
: Negative Supply Output (RS232 Drivers). V
–
≈ –
(2V
CC
– 2.5V). This pin requires an external charge storage
capacitor C ≥ 0.1µF. Larger value capacitors may be used
to reduce supply ripple. With multiple transceivers, the V
+
and V
–
pins may be paralleled into common capacitors.
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
CC
.
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.
6
LT1280A/LT1281A
ESD PROTECTIO
U
The RS232 line inputs of the LT1280A/LT1281A have on-
chip protection from ESD transients up to ±10kV. The
protection structures act to divert the static discharge
safely to system ground. In order for the ESD protection to
function effectively, the power supply and ground pins of
the circuit must be connected to ground through low
impedances. The power supply decoupling capacitors and
charge pump storage capacitors provide this low imped-
ance in normal application of the circuit. The only con-
straint is that low ESR capacitors must be used for
bypassing and charge storage. ESD testing must be done
with pins V
CC
, V
L
, V
+
, V
–
, and GND shorted to ground or
connected with low ESR capacitors.
ESD Test Circuit
1280A ESD TC
0.1µF
RS232
LINE PINS
PROTECTED
TO ±10kV
1
2
3
4
18
17
16
15
14
13
12
11
10
0.1µF
0.1µF
0.1µF
NC
C1+
V+
C1–
C2+
C2–
V–
DR2 OUT
LT1280A
0.1µF
ON/OFF
5V VCC
GND
DR1 OUT
RX1 IN
RX1 OUT
DR1 IN
DR2 IN
RS232 
LINE PINS 
PROTECTED 
TO ±10kV
RX2 IN RX2 OUT
++
+
+
+5
6
7
8
9
U
A
O
PPLICATITYPICAL
Supporting an LT1039 (Triple Driver/Receiver)
30k
30k
RS232 OUTPUT
RS232 OUTPUT
RS232 INPUT
RS232 INPUT
LT1280A • TA04
LT1039
TTL INPUT
30k
RS232 INPUT
V
CC
TTL INPUT
TTL INPUT
TTL OUTPUT
TTL OUTPUT
TTL OUTPUT
ON/OFF
RS232 OUTPUT
5k
RS232 OUTPUT
RS232 INPUT
LT1280A
TTL INPUT
5k
RS232 INPUT
V
CC
TTL INPUT
TTL OUTPUT
TTL OUTPUT
ON/OFF
RS232 OUTPUT
1µF
2
4
1µF
5
6
3
7
18 17
1µF1µF
GND
16
GND
10
V
+
V
–
1
9
18 17
5V
SHUTDOWN
C2
–
C2
+
C1
–
C1
+
V
+
V
–
11
12
13
10
15
14
9
8
12
14
16
11
13
15
7
5
3
8
6
4
+
+
+
+
7
LT1280A/LT1281A
PACKAGE DESCRIPTIO
U
Dimensions in inches (millimeters) unless otherwise noted.
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
S16 (WIDE) 0396
NOTE 1
0.398 – 0.413*
(10.109 – 10.490)
16 15 14 13 12 11 10 9
12345678
0.394 – 0.419
(10.007 – 10.643)
0.037 – 0.045
(0.940 – 1.143)
0.004 – 0.012
(0.102 – 0.305)
0.093 – 0.104
(2.362 – 2.642)
0.050
(1.270)
TYP 0.014 – 0.019
(0.356 – 0.482)
TYP
0° – 8°
TYP
NOTE 1
0.009 – 0.013
(0.229 – 0.330) 0.016 – 0.050
(0.406 – 1.270)
0.291 – 0.299**
(7.391 – 7.595)
× 45°
0.010 – 0.029
(0.254 – 0.737)
NOTE:
1. PIN 1 IDENT, NOTCH ON TOP AND CAVITIES ON THE BOTTOM OF PACKAGES ARE THE MANUFACTURING OPTIONS.
THE PART MAY BE SUPPLIED WITH OR WITHOUT ANY OF THE OPTIONS
DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
*
**
SW Package
16-Lead Plastic Small Outline (Wide 0.300)
(LTC DWG # 05-08-1620)
N Package
16-Lead PDIP (Narrow 0.300)
(LTC DWG # 05-08-1510)
N16 1197
0.770*
(19.558)
MAX
16
12345678
910
11
12
13
14
15
0.255 ± 0.015*
(6.477 ± 0.381)
0.020
(0.508)
MIN
0.125
(3.175)
MIN
0.130 ± 0.005
(3.302 ± 0.127)
0.065
(1.651)
TYP
0.045 – 0.065
(1.143 – 1.651)
0.018 ± 0.003
(0.457 ± 0.076)
0.100 ± 0.010
(2.540 ± 0.254)
0.009 – 0.015
(0.229 – 0.381)
0.300 – 0.325
(7.620 – 8.255)
0.325 +0.035
–0.015
+0.889
–0.381
8.255
()
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)
N Package
18-Lead PDIP (Narrow 0.300)
(LTC DWG # 05-08-1510)
N18 1197
0.255 ± 0.015*
(6.477 ± 0.381)
0.900*
(22.860)
MAX
18
123456789
1011
121314
16 1517
0.020
(0.508)
MIN
0.125
(3.175)
MIN
0.130 ± 0.005
(3.302 ± 0.127)
0.065
(1.651)
TYP
0.045 – 0.065
(1.143 – 1.651)
0.018 ± 0.003
(0.457 ± 0.076)
0.005
(0.127)
MIN
0.100 ± 0.010
(2.540 ± 0.254)
0.009 – 0.015
(0.229 – 0.381)
0.300 – 0.325
(7.620 – 8.255)
0.325 +0.035
–0.015
+0.889
–0.381
8.255
()
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)
8
LT1280A/LT1281A
PACKAGE DESCRIPTIO
U
Dimensions in inches (millimeters) unless otherwise noted.
LINEAR TECHNOLOGY CORPORATION 1993
SW Package
18-Lead Plastic Small Outline (Wide 0.300)
(LTC DWG # 05-08-1620)
S18 (WIDE) 0396
SEE
NOTE
0.447 – 0.463*
(11.354 – 11.760)
15 14 13 12 11 10
16
9
12345678
0.394 – 0.419
(10.007 – 10.643)
1718
0.037 – 0.045
(0.940 – 1.143)
0.004 – 0.012
(0.102 – 0.305)
0.093 – 0.104
(2.362 – 2.642)
0.050
(1.270)
TYP 0.014 – 0.019
(0.356 – 0.482)
TYP
0° – 8°
TYP
NOTE 1
0.009 – 0.013
(0.229 – 0.330)
0.016 – 0.050
(0.406 – 1.270)
0.291 – 0.299**
(7.391 – 7.595)
× 45°
0.010 – 0.029
(0.254 – 0.737)
NOTE:
1. PIN 1 IDENT, NOTCH ON TOP AND CAVITIES ON THE BOTTOM OF PACKAGES ARE THE MANUFACTURING OPTIONS.
THE PART MAY BE SUPPLIED WITH OR WITHOUT ANY OF THE OPTIONS
DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
*
**
U
A
O
PPLICATITYPICAL
12801afa LT/TP 1098 REV A 2K • PRINTED IN USA
5k
5k
0.1µF
0.1µF
LOGIC
INPUTS
LOGIC
OUTPUTS
ON/OFF 18
10
13
11
12
6
5
4
2
16
9
14
8
15
7
3
17 5V INPUT
–12V
OUT
RS232 OUTPUT
RS232 OUTPUT
RS232 INPUT
RS232 INPUT
LT1280A • TA03
LT1280A
12V INPUT
+
+
Operation Using 5V and 12V Power Supplies
PART NUMBER DESCRIPTION COMMENTS
LT1180A/LT1181A 5V 2-Driver/2-Receiver RS232 Transceivers Pin Compatible with LT1280A/LT1280A
LT1381 5V 2-Driver/2-Receiver RS232 Transceiver Narrow 16-Pin SO Package
LT1780/LT1781 5V 2-Driver/2-Receiver RS232 Transceiver IEC 1000-4-2 Level 4 Compliance
RELATED PARTS
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507
●
www.linear-tech.com