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Электронный компонент: LT1081IN

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1
LT1080/LT1081
Advanced Low Power
5V RS232 Dual Driver/Receiver
The LT
1080/LT1081 are the only dual RS232 driver/
receiver with charge pump to guarantee absolutely no
latchup. These interface optimized devices provide a real-
istic balance between CMOS levels of power dissipation
and real world requirements for ruggedness. The driver
outputs are fully protected against overload and can be
shorted to
30V. Unlike CMOS, the advanced architecture
of the LT1080/LT1081 does not load the signal line when
"shut down" or when power is off. Both the receiver and
RS232 outputs are put into a high impedance state. An
advanced output stage allows driving higher capacitive
loads at higher speeds with exceptional ruggedness
against ESD.
For applications requiring up to five drivers and five
receivers with charge pump in one package see the LT1130A
Series data sheet. A version of the LT1080/LT1081, the
LT1180A and LT1181A that use only 0.1
F capacitors, is
also available. All of Linear Technology's RS232 ICs are
available in standard surface mount packages.
s
Superior to CMOS
Improved Speed: Operates over 120kBaud
Improved Protection: Outputs Can Be Forced
to
30V without Damage
Three-State Outputs Are High
Impedance When Off
Only Needs 1
F Capacitors
s
Absolutely No Latchup
s
CMOS Comparable Low Power: 60mW
s
Can Power Additional RS232 Drivers: 10mA
s
Supply Current in Shutdown: 1
A
s
Available in SO Package
s
Available with or without Shutdown
, LTC and LT are registered trademarks of Linear Technology Corporation.
s
Portable Computers
s
Battery-Powered RS232 Systems
s
Power Supply Generator
s
Terminals
s
Modems
Supply Generator Outputs
OUTPUT CURRENT (mA)
0
2
4
6
8
10 12 14 16 18 20
OUTPUT VOLTAGE (V)
1080/81 TA01a
10
8
6
4
2
0
2
4
6
8
10
V
CC
= 5V
V
+
OUTPUT
R
L
TO V
R
L
TO GND
R
L
TO GND
R
L
TO V
+
V
OUTPUT
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
9V OUTPUT
9V OUTPUT
RS232 OUTPUT
RS232 OUTPUT
RS232 INPUT
RS232 INPUT
1080/81 TA01
5k
5k
LT1080
1
F
1
F
1
F
1
F
FEATURES
DESCRIPTIO
U
APPLICATIO S
U
TYPICAL APPLICATIO
U
2
LT1080/LT1081
A
U
G
W
A
W
U
W
A
R
BSOLUTE
XI
TI
S
Supply Voltage (V
CC
) ................................................. 6V
V
+ ...........................................................................................
12V
V
.......................................................................................
12V
Input Voltage
Driver ........................................................... V
to V
+
Receiver ................................................. 30V to 30V
ON/OFF Pin .............................................. GND 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
LT1080C/LT1081C ................................. 0
C to 70
C
LT1080I/LT1081I ................................ 40
C to 85
C
LT1080M/LT1081M .......................... 55
C to 125
C
Storage Temperature Range ..................65
C to 150
C
Lead Temperature (Soldering, 10 sec)................. 300
C
LT1081CJ
LT1081CN
LT1081CSW
LT1081IN
LT1081ISW
LT1081MJ
LT1080CJ
LT1080CN
LT1080CSW
LT1080IN
LT1080ISW
LT1080MJ
ORDER PART
NUMBER
ORDER PART
NUMBER
T
JMAX
= 150
C,
JA
= 100
C/W,
JC
= 40
C/W (J)
T
JMAX
= 150
C,
JA
= 120
C/W,
JC
= 50
C/W (N)
T
JMAX
= 150
C,
JA
= 90
C/W,
JC
= 26
C/W (SW)
W
U
U
PACKAGE/ORDER I FOR ATIO
T
JMAX
= 150
C,
JA
= 100
C/W,
JC
= 40
C/W (J)
T
JMAX
= 150
C,
JA
= 120
C/W,
JC
= 50
C/W (N)
T
JMAX
= 150
C,
JA
= 95
C/W,
JC
= 27
C/W (SW)
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
J PACKAGE
16-LEAD CERDIP
N PACKAGE
16-LEAD PDIP
SW PACKAGE
16-LEAD PLASTIC SO WIDE
LT1081
1
2
3
4
5
6
7
8
9
TOP VIEW
J PACKAGE
18-LEAD CERDIP
N PACKAGE
18-LEAD PDIP
SW PACKAGE
18-LEAD PLASTIC SO WIDE
18
17
16
15
14
13
12
11
10
NC
C1
+
V
+
C1
C2
+
C2
V
TR2 OUT
REC2 IN
ON/OFF
V
CC
GND
TR1 OUT
REC1 IN
REC1 OUT
TR1 IN
TR2 IN
REC2 OUT
LT1080
(Note 1)
3
LT1080/LT1081
ELECTRICAL C
C
HARA TERISTICS
The
q
denotes the specifications which apply over the full operating
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Driver
Output Voltage Swing
Load = 3k to GND Both Outputs
Positive
q
5
7.3
V
Negative
q
5
6.5
V
Logic Input Voltage Level
Input Low Level (V
OUT
= High)
q
1.4
0.8
V
Input High Level (V
OUT
= Low)
q
2
1.4
V
Logic Input Current
V
IN
2V
q
5
20
A
V
IN
0.8V
q
5
20
A
Output Short-Circuit Current
Sourcing Current, V
OUT
= 0V
9
12
mA
Sinking Current, V
OUT
= 0V
9
12
mA
Output Leakage Current
SHUTDOWN (Note 3), V
OUT
=
30V
q
10
100
A
Data Rate (Note 6)
R
L
= 3k, C
L
= 2500pF
120
kBd
R
L
= 3k, C
L
= 1000pF
250
kBd
Slew Rate
R
L
= 3k, C
L
= 51pF
4
15
30
V/
s
Receiver
Input Voltage Thresholds
Input Low Threshold
Commercial
q
0.8
1.3
V
Industrial and Military
q
0.2
1.3
V
Input High Threshold
Commercial
q
1.7
2.4
V
Industrial and Military
q
1.7
3.0
V
Hysteresis
q
0.1
0.4
1
V
Input Resistance
V
IN
=
10V
3
5
7
k
Output Voltage
Output Low, I
OUT
= 1.6mA
q
0.2
0.4
V
Output High, I
OUT
= 160
A (V
CC
= 5V)
q
3.5
4.8
V
Output Short-Circuit Current
Sinking Current, V
OUT
= V
CC
10
20
mA
Sourcing Current, V
OUT
= 0V
0.6
1
mA
Output Leakage Current
SHUTDOWN (Note 3), 0V
V
OUT
V
CC
q
1
10
A
Power Supply Generator (Note 4)
V
+
Output Voltage
I
OUT
= 0mA
8.0
9.0
V
I
OUT
= 10mA
7.0
8.0
V
I
OUT
= 15mA
6.5
7.5
V
V
Output Voltage
I
OUT
= 0mA
7.5
8.5
V
I
OUT
= 10mA
5.5
6.5
V
I
OUT
= 15mA
5.0
6.0
V
Supply Current
q
12
22
mA
Supply Leakage Current (V
CC
)
SHUTDOWN (Note 3), LT1080 Only
q
1
100
A
ON/OFF Pin Current
0V
V
ON/OFF
5V, LT1080 Only
q
15
80
A
Supply Rise Time
(Note 5), LT1080 Only
1
ms
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: These parameters apply for 4.5V
V
CC
5.5V and V
ON/OFF
= 3V,
unless otherwise specified.
Note 3: V
ON/OFF
= 0.4V for 55
C
T
A
50
C, and V
ON/OFF
= 0.2V for
50
C
T
A
125
C. (LT1080 only)
Note 4: Unless otherwise specified, V
CC
= 5V, external loading of V
+
and
V
equals zero and the driver outputs are low (inputs high).
Note 5: Time from either SHUTDOWN high or power on until V
+
6V and
V
6V. All external capacitors are 1
F.
Note 6: Data rate operation guaranteed by slew rate, short-circuit current
and propagation delay tests.
temperature range, otherwise specifications are at T
A
= 25
C. (Note 2)
4
LT1080/LT1081
PI FU CTIO S
U
U
U
(Pin numbers refer to LT1080)
TEMPERATURE (
C)
55
25
0
25
50
75
100
125
DRIVER OUTPUT VOLTAGE (V)
1080/81 G01
10
8
6
4
2
0
2
4
6
8
10
V
CC
= 5.5V
V
CC
= 4.5V
R
L
= 3k
OUTPUT HIGH
V
CC
= 5.5V
V
CC
= 4.5V
OUTPUT LOW
V
CC
= 5V
V
CC
= 5V
TIME (ms)
0
0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
SUPPLY VOLTAGE (V)
1080/81 G03
10
8
6
4
2
0
2
4
6
8
10
V
+
SUPPLY
V
CC
= 5V
C1 TO C4 = 1
F
R
L
= 4.7k; V
+
TO V
V
SUPPLY
OUTPUT CURRENT (mA)
0
2
4
6
8
10 12 14 16 18 20
OUTPUT VOLTAGE (V)
1080/81 G02
10
8
6
4
2
0
2
4
6
8
10
V
CC
= 5V
V
+
OUTPUT VOLTAGE
LOADED TO V
LOADED TO GROUND
LOADED TO GROUND
LOADED TO V
+
V
OUTPUT VOLTAGE
Driver Output Voltage
Supply Generator Outputs
Supply Generation from V
CC
or Shutdown
C1
+
; C1
; C2
+
; C2
(Pins 2, 4, 5, 6): Requires an external
capacitor (
1
F) from C1
+
to C1
and another from C2
+
to C2
. Pin 2 can be used for connecting a second positive
supply. When a separate positive supply is used, C1 can be
deleted.
V
+
(Pin 3): Positive Supply for RS232 Drivers.
V
+
2V
CC
1.5V. Requires an exterenal capacitor (
1
F)
for charge storage. May be loaded (up to 15mA) for
external system use. Loading does reduce V
+
voltage (see
graphs). Capacitor may be tied to ground or +5V input
supply. With multiple transceivers, the V
+
and V
pins may
be paralleled into common capacitors.
V
(Pin 7): Negative Supply for RS232 Drivers.
V
(2V
CC
2.5V). Requires an external capacitor
(
1
F) for charge stroage. May be loaded (up to 15mA)
for external system use. Loading does reduce V
voltage
(see graphs). With multiple transceivers, the V
+
and V
pins may be paralleled into common capacitors.
TR2 OUT; TR1 OUT (Pins 8, 15): Driver Outputs with
RS232 Voltage Levels. Outputs are in a high impedance
state when in the SHUTDOWN mode or when power is off
(V
CC
= 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. Shorting one output will affect output from the
other.
REC2 IN; REC1 IN (Pins 9, 14): Receiver Inputs. Accepts
RS232 voltage levels (
30V) and has 0.4V of hysteresis to
provide noise immunity. Input impedance is nominally
5k
.
REC2 OUT; REC1 OUT (Pins 10, 13): 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.
TR2 IN; TR1 IN (Pins 11, 12): RS232 Driver Input Pins.
Inputs are TTL/CMOS compatible. Inputs should not be
allowed to float. Tie unused inputs to V
CC
.
GND (Pin 16): Ground Pin.
V
CC
(Pin 17): Input Supply Pin. Supply current drops to
zero in the SHUTDOWN mode.
ON/OFF (Pin 18): Contols the operation mode of the
LT1080 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. A logic high fully
enables the device.
TYPICAL PERFOR A CE CHARACTERISTICS
U
W
5
LT1080/LT1081
TYPICAL PERFOR A CE CHARACTERISTICS
U
W
TEMPERATURE (
C)
55
25
0
25
50
75
100
125
INPUT THRESHOLD (V)
1080/81 G04
3.00
2.75
2.50
2.25
2.00
1.75
1.50
1.25
1.00
0.75
0.50
INPUT HIGH
INPUT LOW
INPUT VOLTAGE (V)
0
1
2
3
4
5
INPUT CURRENT (
A)
1080/81 G06
40
35
30
25
20
15
10
5
0
5
10
Receiver Input Thresholds
Receiver Output
Short-Circuit Current
ON/OFF Pin Current vs Voltage
TEMPERATURE (
C)
OUTPUT CURRENT (mA)
100
10
1
0.1
1080/81 G05
OUTPUT SOURCING
OUTPUT SINKING
55
25
0
25
50
75
100
125
ON/OFF Pin Thresholds
Supply Current in Shutdown
Driver Output Leakage in
Shutdown
TEMPERATURE (
C)
55
25
0
25
50
75
100
125
ON/OFF PIN VOLTAGE (V)
1080/81 G07
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
MAXIMUM OFF VOLTAGE
MINIMUM ON VOLTAGE
TEMPERATURE (
C)
SUPPLY CURRENT (nA)
1000
100
10
1
1080/81 G08
V
CC
= 5V
55
25
0
25
50
75
100
125
TEMPERATURE (
C)
OUTPUT LEAKAGE CURRENT (
A)
100
10
1
0.1
1080/81 G09
V
OUT
= 30V
V
OUT
= 30V
55
25
0
25
50
75
100
125
Output Waveforms
Shutdown to Receiver Output
0
2
s
4
s
6
s
8
s
0
1ms
2ms
3ms
4ms
0
1ms
2ms
3ms
4ms
V
CC
= 5V
1080/81 G11.tiff
V
CC
= 5V
1080/81 G11.tiff
R
L
= 3k
V
CC
= 5V
1080/81 G10.tiff
R
L
= 3k
5V
0V
RECEIVER
OUTPUT
LOW
0V
5V
10
ON/OFF
INPUT
10V
5V
0V
DRIVER
OUTPUT
HIGH
INPUT
5V
0V
DRIVER
OUTPUT
5V
0V
5V
RECEIVER
OUTPUT
5V
0V
Shutdown to Driver Output
6V
4V
2V
0V
RECEIVER
OUTPUT
ON/OFF
INPUT
5V
0V