LINER LT1381CN Low power 5v rs232 dual driver/receiver with 0.1uf capacitor Datasheet

LT1381
Low Power 5V RS232 Dual
Driver/Receiver with
0.1µF Capacitors
U
DESCRIPTIO
FEATURES
■
■
■
■
■
■
■
■
■
■
■
ESD Protection over ±10kV
Low Cost
Uses Small Capacitors: 0.1µF
CMOS Comparable Low Power: 40mW
Operates from a Single 5V Supply
120kBaud Operation for RL = 3k, CL = 2500pF
250kBaud Operation for RL = 3k, CL = 1000pF
Rugged Bipolar Design
Outputs Assume a High Impedance State When
Powered Down
Absolutely No Latchup
Available in Narrow SO Package
UO
APPLICATI
■
■
■
■
Portable Computers
Battery-Powered Systems
Power Supply Generator
Terminals
Modems
, LTC and LT are registered trademarks of Linear Technology Corporation.
TransZorb® is a registered trademark of General Instruments, GSI
UO
■
S
The LT ®1381 is a dual RS232 driver/receiver pair with
integral charge pump to generate RS232 voltage levels
from a single 5V supply. The circuit features rugged
bipolar design to provide operating fault tolerance and
ESD protection unmatched by competing CMOS designs.
Using only 0.1µF external capacitors, the circuit consumes only 40mW of power and can operate to 120kbaud
even while driving heavy capacitive loads. New ESD structures on the chip allow the LT1381 to survive multiple
±10kV strikes, eliminating the need for costly TransZorbs®
on the RS232 line pins. Driver outputs are protected from
overload and can be shorted to ground or up to ±25V
without damage. During power-off conditions, driver and
receiver outputs are in a high impedance state, allowing
line sharing.
TYPICAL APPLICATI
+
0.1µF
1
16
3
2
5V INPUT
V + OUT
+
0.1µF
LT1381
+
0.1µF
LOGIC
INPUTS
4
6
V – OUT
+
5
11
14
10
7
12
13
Output Waveforms
DRIVER
OUTPUT
RL = 3k
CL = 2500pF
0.1µF
RS232 OUTPUT
RECEIVER
R OUTPUT
CL = 50pF
RS232 OUTPUT
RS232 INPUT
INPUT
5k
LOGIC
OUTPUTS
9
8
S
5k
RS232 INPUT
LT1381 • TA02
15
LT1381 • TA01
1
LT1381
U
U
RATI GS
W
W W
W
AXI U
U
ABSOLUTE
PACKAGE/ORDER I FOR ATIO
(Note 1)
Supply Voltage (VCC) ................................................ 6V
V + ........................................................................ 13.2V
V – ...................................................................... –13.2V
Input Voltage
Driver ........................................................... V – to V +
Receiver ............................................... – 30V to 30V
Output Voltage
Driver ................................. (V+ – 30V) to (V – + 30V)
Receiver ................................. – 0.3V to (VCC + 0.3V)
Short-Circuit Duration
V + ................................................................... 30 sec
V – ................................................................... 30 sec
Driver Output .............................................. Indefinite
Receiver Output .......................................... Indefinite
Operating Temperature Range
LT1381C ................................................. 0°C to 70°C
LT1381I .............................................. – 40°C to 85°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
ELECTRICAL CHARACTERISTICS
ORDER PART
NUMBER
TOP VIEW
C1+
1
16 VCC
V+
2
15 GND
–
3
14 TR1 OUT
C2+
4
13 REC1 IN
–
5
12 REC1 OUT
V–
6
11 TR1 IN
TR2 OUT
7
10 TR2 IN
REC2 IN
8
9
C1
C2
REC2 OUT
S PACKAGE
N PACKAGE
16-LEAD PLASTIC DIP 16-LEAD PLASTIC SOIC
TJMAX = 125°C, θJA = 90°C/ W, θJC = 46°C/W (N)
TJMAX = 125°C, θJA = 110°C/ W, θJC = 34°C/W (S)
Consult factory for Military grade parts.
(Note 2)
PARAMETER
Power Supply Generator
V + Output
V – Output
Supply Current (VCC)
CONDITIONS
Supply Rise Time
Oscillator Frequency
Driver
Output Voltage Swing
C1 = C2 = C3 = C4 = 0.1µF
MIN
(Note 3), TA = 25°C
Load = 3k to GND
●
Positive
Negative
●
●
5.0
●
●
Logic Input Current
0.8V ≤ VIN ≤ 2.0V
●
Output Short-Circuit Current
VOUT = 0V
Output Leakage Current
Power Off VOUT = ±15V
Data Rate
RL = 3k, CL = 2500pF
RL = 3k, CL = 1000pF
120
250
Slew Rate
RL = 3k, CL = 51pF
RL = 3k, CL = 2500pF
4
2
MAX
14
16
0.2
130
Input Low Level (VOUT = High)
Input High Level (VOUT = Low)
Output Transition tHL High to Low (Note 4)
Output Transition tLH Low to High
TYP
7.9
– 7.0
8
Logic Input Voltage Level
Propagation Delay
LT1381CN
LT1381CS
LT1381IS
2.0
9
V
V
mA
mA
ms
kHz
7.5
– 6.3
1.4
1.4
– 5.0
0.8
V
V
V
V
5
20
µA
17
10
●
UNITS
mA
100
µA
kBaud
kBaud
15
6
30
V/µs
V/µs
0.6
0.5
1.3
1.3
µs
µs
LT1381
ELECTRICAL CHARACTERISTICS
PARAMETER
(Note 2)
CONDITIONS
MIN
TYP
MAX
UNITS
Input Low Threshold (VOUT = High)
Input High Threshold (VOUT = Low)
0.8
1.3
1.7
2.4
V
V
0.4
1.0
V
Receiver
Input Voltage Thresholds
Hysteresis
0.1
●
Input Resistance
(Note 6)
Output Voltage
Output Low, IOUT = – 1.6mA
Output High, IOUT = 160µA (VCC = 5V)
Output Short-Circuit Current
●
●
Sinking Current, VOUT = VCC
Sourcing Current, VOUT = 0V
Propagation Delay
3
5
7
0.4
3.5
0.2
4.2
V
V
– 20
20
– 10
10
mA
mA
250
350
600
600
ns
ns
Output Transition tHL High-to-Low (Note 5)
Output Transition tLH Low-to-High
The ● denotes specifications which apply over the full operating
temperature range.
Note 1: Absolute Maximum Ratings are those values beyond which the life
of the device may be impaired.
Note 2: Testing done at VCC = 5V, 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.
kΩ
Note 4: For driver delay measurements, RL = 3k and CL = 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 5: For receiver delay measurements, CL = 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 6: Tested at VIN = ±10V.
W U
TYPICAL PERFOR A CE CHARACTERISTICS
Driver Maximum Output Voltage
vs Load Capacitance
Driver Minimum Output Voltage
vs Load Capacitance
2 DRIVERS LOADED
2 DRIVERS LOADED
8.5
8
120k BAUD
8.0
7.5
20k BAUD
7.0
6.5
60k BAUD
6.0
DRIVER OUTPUT VOLTAGE (V)
–4.5
PEAK OUTPUT VOLTAGE (V)
PEAK OUTPUT VOLTAGE (V)
Driver Output Voltage
10
–4.0
9.0
–5.0
60k BAUD
–5.5
–6.0
20k BAUD
–6.5
5.5
–7.0
0
1
2
6
4
2
0
–2
–4
VCC = 5.5V
VCC = 5V
VCC = 4.5V
OUTPUT HIGH
OUTPUT LOW
VCC = 4.5V
VCC = 5V
VCC = 5.5V
–6
–8
120k BAUD
5.0
RL = 3k
3 4 5 6 7 8
LOAD CAPACITANCE (nF)
9
10
LT1381 • TPC01
0
1
2
3 4 5 6 7 8
LOAD CAPACITANCE (nF)
9
10
LT1381 • TPC02
–10
–55 –25
50
25
0
75
TEMPERATURE (°C)
100
125
LT1381 • TPC03
3
LT1381
W U
TYPICAL PERFOR A CE CHARACTERISTICS
Supply Current vs Data Rate
Receiver Input Threshold
3.00
100
2.50
SUPPLY CURRENT (mA)
40
2.25
INPUT HIGH
2.00
1.75
1.50
INPUT LOW
1.25
1.00
LEAKAGE CURRENT (µA)
2 DRIVERS ACTIVE
RL = 3k
CL = 2500pF
2.75
THRESHOLD VOLTAGE (V)
Driver Leakage in Shutdown
50
30
20
10
VOUT = 30V
1
VOUT = –30V
10
0.75
0.50
–55 –25
50
25
0
75
TEMPERATURE (°C)
100
0
125
0
25
50
75
100
DATA RATE (kBaud)
125
LT1381 • TPC04
0.1
–55 –25
150
LT1381 • TPC05
Receiver Short-Circuit Current
100
125
LT1381 • TPC06
Driver Short-Circuit Current
50
Slew Rate vs Load Capacitance
30
20
ISC –
18
40
30
ISC +
20
10
25
16
ISC +
SLEW RATE (V/µs)
SHORT-CIRCUIT CURRENT (mA)
SHORT-CIRCUIT CURRENT (mA)
50
25
0
75
TEMPERATURE (°C)
20
15
ISC –
10
14
12
10
8
+SLEW RATE
6
4
5
–SLEW RATE
2
0
–55 –25
50
25
0
75
TEMPERATURE (°C)
100
125
0
–55 –25
50
25
75
0
TEMPERATURE (˚C)
LTLT1381 • TPC07
100
125
0
0
1
3
2
CAPACITANCE (nF)
V – Compliance Curve
10
–10
V + (1µF)
8
–8
V – (1µF)
6
V – (V)
V + (V)
V + (0.1µF)
V – (0.1µF)
–4
2
–2
0
0
5
10
LOAD CURRENT + (mA)
15
LT1381 • TPC10
4
–6
4
0
0
5
LT1381 • TPC09
LT1381 • TPC08
V + Compliance Curve
4
5
10
LOAD CURRENT – (mA)
15
LT1381 • TPC11
LT1381
U
U
U
PI FU CTIO S
C1 +, C1 –, C2 +, C2 – (Pins 1, 3, 4, 5): Commutating
Capacitor Inputs. These pins require two external capacitors C ≥ 0.1µF: one from C1+ to C1– and another from C2+
to C2 –. C1 may be deleted if a separate 12V supply is
available and connected to pin C1+.
V + (Pin 2): Positive Supply Output (RS232 Drivers).
V + ≈ 2VCC – 2.1V. This pin requires an external charge
storage capacitor C ≥ 0.1µF, tied to ground or VCC. Larger
value capacitors may be used to reduce supply ripple. With
multiple transceivers, the V+ and V – pins may be paralleled
into common capacitors.
V – (Pin 6): Negative Supply Output (RS232 Drivers).
V – ≈ –(2VCC – 3V). 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.
TR2 OUT, TR1 OUT (Pin 7, 14): 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. Output current capability is sufficient for
load conditions up to 2500pF. Outputs are in a high
impedance state when VCC = 0V. Outputs are fully shortcircuit protected from V – + 25V to V + – 25V. 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.
REC2 IN, REC1 IN (Pins 8, 13): Receiver Inputs. These
pins accept RS232 level signals (±30V) into a protected 5k
terminating 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.
REC2 OUT, REC1 OUT (Pins 9, 12): Receiver Outputs with
TTL/CMOS Voltage Levels. Outputs are fully short-circuit
protected to ground or VCC with the power ON or OFF.
TR2 IN, TR1 IN (Pins 10, 11): RS232 Driver Input Pins.
These inputs are TTL/CMOS compatible. Inputs should
not be allowed to float. Tie unused inputs to VCC.
GND (Pin 15): Ground Pin.
VCC (Pin 16): 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.
U
ESD PROTECTIO
The RS232 line inputs of the LT1381 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 impedance in normal
application of the circuit. The only constraint is that low
ESR capacitors must be used for bypassing and charge
storage. ESD testing must be done with pins VCC, V +, V –
and GND shorted to ground or connected with low ESR
capacitors.
ESD Test Circuit
1
0.1µF
+
+2
0.1µF
+
0.1µF
RS232
LINE PINS
PROTECTED
TO ±10kV
V+
5V VCC
LT1381
GND
16
+
15
3
C1–
TR1 OUT 14
4
C2+
REC1 IN 13
5
C2 –
REC1 OUT 12
6
V–
0.1µF
+
C1+
7 TR2 OUT
8 REC2 IN
0.1µF
RS232
LINE PINS
PROTECTED
TO ±10kV
TR1 IN 11
TR2 IN 10
REC2 OUT 9
LT1381 • ESD TC
5
LT1381
U
TYPICAL APPLICATIO S
Isolated RS232 Driver/Receiver
CTX20-1
1:1
VIN = 5V
±10% FROM
SYSTEM
ILIM
100µF
1Ω
VIN
+
13.7V
10k
+
FB
ISOLATOR OUTPUT
(DATA TO SYSTEM)
1µF
SW2
1k
16 VCC
1
VCC
OS
10µF
1N5818
LT1111
VOUT
0.1µF
100µF
SW1
GND
5V ±10%
LT1121-5
+
L1
20µH
47Ω
+
1N5818
+
IN
0.1µF
3
LTC1145
LT1381
RS232
2
+
4
GND2
GND1
0.1µF
+
0.1µF
5
6
+
ISOLATOR INPUT
(DATA FROM SYSTEM)
VIN
9
VCC
IN
RX
OS
LTC1145
GND1
11
DX
8
14
0.1µF
RS232 INPUT
RS232 OUTPUT
15
GND2
FLOATING GROUND
LT1381 • TA03
ISOLATION BARRIER
SYSTEM GROUND
Data Transmission Across Isolation Barrier
ISOLATOR
INPUT
RS232
INPUT
RS232
OUTPUT
ISOLATOR
OUTPUT
1381 TA04
6
1381 TA05
LT1381
U
PACKAGE DESCRIPTIO
Dimensions in inches (millimeters) unless otherwise noted.
N Package
16-Lead PDIP (Narrow 0.300)
(LTC DWG # 05-08-1510)
0.770*
(19.558)
MAX
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
0.255 ± 0.015*
(6.477 ± 0.381)
0.130 ± 0.005
(3.302 ± 0.127)
0.300 – 0.325
(7.620 – 8.255)
0.020
(0.508)
MIN
0.009 – 0.015
(0.229 – 0.381)
(
+0.035
0.325 –0.015
8.255
+0.889
–0.381
0.045 – 0.065
(1.143 – 1.651)
)
0.065
(1.651)
TYP
0.125
(3.175)
MIN
0.018 ± 0.003
(0.457 ± 0.076)
0.100 ± 0.010
(2.540 ± 0.254)
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)
N16 1197
S Package
16-Lead Plastic Small Outline (Narrow 0.150)
(LTC DWG # 05-08-1610)
0.386 – 0.394*
(9.804 – 10.008)
16
15
14
13
12
11
10
9
0.150 – 0.157**
(3.810 – 3.988)
0.228 – 0.244
(5.791 – 6.197)
1
0.010 – 0.020
× 45°
(0.254 – 0.508)
0.008 – 0.010
(0.203 – 0.254)
2
3
4
5
6
0.053 – 0.069
(1.346 – 1.752)
0.014 – 0.019
(0.355 – 0.483)
8
0.004 – 0.010
(0.101 – 0.254)
0° – 8° TYP
0.016 – 0.050
0.406 – 1.270
7
0.050
(1.270)
TYP
S16 0695
*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
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 representation that the interconnection of circuits as described herein will not infringe on existing patent rights.
7
LT1381
U
TYPICAL APPLICATIO S
Operation Using 5V and 12V Power Supplies
12V INPUT
+
0.1µF
LOGIC
INPUTS
1
16
2
3
LT1381
4
5V INPUT
16
–12VOUT
+
5
11
14
10
7
12
13
0.1µF
RS232 OUTPUT
RS232 OUTPUT
RS232 INPUT
5k
LOGIC
OUTPUTS
9
8
S
5k
RS232 INPUT
15
LT1381 • TA06
Sharing Capacitors
5V VCC
TTL INPUT
TTL INPUT
TTL OUTPUT
16
V+
LT1381
V–
2
5V VCC
6
11
14
10
7
12
13
16
LT1381
+
RS232 OUTPUT
+
RS232 OUTPUT
RS232 INPUT
0.1µF
TTL INPUT
TTL INPUT
TTL OUTPUT
9
1
6
10
7
12
13
RS232 OUTPUT
RS232 OUTPUT
RS232 INPUT
5k
8
RS232 INPUT
TTL OUTPUT
9
8
RS232 INPUT
5k
4
C1+
C2+
C1–
5
C2 –
0.1µF
3
V–
14
5k
+
2
11
5k
TTL OUTPUT
V+
1
+
+
0.1µF
4
C1+
C2+
C1–
5
C2 –
+
0.1µF
3
0.1µF
LT1381 • TA07
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LT1180A/LT1181A
5V 2-Driver/2-Receiver RS232 Transceivers
Pin Compatible with LT1280A/LT1280A
LT1280A/LT1281A
5V 2-Driver/2-Receiver RS232 Transceivers
Pin Compatible with LT1180A/LT1181A
LT1780/LT1781
5V 2-Driver/2-Receiver RS232 Transceivers
IEC 1000-4-2 Level 4 Compliance
8
Linear Technology Corporation
1381fa, sn1381 LT/TP 1098 REV A 2K • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408)432-1900 ● FAX: (408) 434-0507 ● www.linear-tech.com
 LINEAR TECHNOLOGY CORPORATION 1993
Similar pages