NSC DS26LS31CMWC Datasheet
DS26LS31C/DS26LS31M
Quad High Speed Differential Line Driver
General Description
The DS26LS31 is a quad differential line driver designed for
digital data transmission over balanced lines. The
DS26LS31 meets all the requirements of EIA Standard
RS-422 andFederal Standard 1020. It is designed to provide
unipolar differential drive to twisted-pair or parallel-wire
transmission lines.
The circuit provides an enable and disable function common
to all four drivers. The DS26LS31 features TRI-STATE
®
outputs and logically ANDed complementary outputs. The inputs are all LS compatible and are all one unit load.
Features
n Output skew — 2.0 ns typical
n Input to output delay—10 ns typical
n Operation from single 5V supply
n Outputs won’t load line when V
CC
=
0V
n Four line drivers in one package for maximum package
density
n Output short-circuit protection
n Complementary outputs
n Meets the requirements of EIA Standard RS-422
n Pin compatible with AM26LS31
n Available in military and commercial temperature range
Logic and Connection Diagrams
TRI-STATE®is a registered trademark of National Semiconductor Corporation.
DS005778-1
Dual-In-Line Package
DS005778-2
Top View
Order Number DS26LS31CM, or DS26LS31CN
See NS Package M16A or N16E
For Complete Military Product Specifications,
refer to the appropriate SMD or MDS.
Order Number DS26LS31MJ/883, DS26LS31ME/883 or DS26LS31MW/883
See NS Package E20A, J16A or W16A
June 1998
DS26LS31C/DS26LS31M Quad High Speed Differential Line Driver
© 2000 National Semiconductor Corporation DS005778 www.national.com
Absolute Maximum Ratings (Note 2)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage 7V
Input Voltage 7V
Output Voltage 5.5V
Output Voltage (Power OFF) −0.25 to 6V
Maximum Power Dissipation (Note 1) at 25˚C
Cavity Package 1509 mW
Molded DIP Package 1476 mW
SO Package 1051 mW
Operating Conditions
Min Max Units
Supply Voltage, V
CC
DS26LS31M 4.5 5.5 V
DS26LS31 4.75 5.25 V
Temperature, T
A
DS26LS31M −55 +125 ˚C
DS26LS31 0 +70 ˚C
Note 1: Derate cavity package 10.1 mW/˚C above 25˚C; derate molded DIP
package 11.9 mW/˚C above 25˚C; derate SO package 8.41 mW/˚C above
25˚C.
Electrical Characteristics (Notes 3, 4, 5)
Symbol Parameter Conditions Min Typ Max Units
V
OH
Output High Voltage I
OH
=
−20 mA 2.5 V
V
OL
Output Low Voltage I
OL
=
20 mA 0.5 V
V
IH
Input High Voltage 2.0 V
V
IL
Input Low Voltage 0.8 V
I
IL
Input Low Current V
IN
=
0.4V −40 −200 µA
I
IH
Input High Current V
IN
=
2.7V 20 µA
I
I
Input Reverse Current V
IN
=
7V 0.1 mA
I
O
TRI-STATE Output Current V
O
=
2.5V 20 µA
V
O
=
0.5V −20 µA
V
CL
Input Clamp Voltage I
IN
=
−18 mA −1.5 V
I
SC
Output Short-Circuit Current −30 −150 mA
I
CC
Power Supply Current All Outputs Disabled 35 60 mA
or Active
Switching Characteristics
V
CC
=
5V, T
A
=
25˚C
Symbol Parameter Conditions Min Typ Max Units
t
PLH
Input to Output C
L
=
30 pF 10 15 ns
t
PHL
Input to Output C
L
=
30 pF 10 15 ns
Skew Output to Output C
L
=
30 pF 2.0 6.0 ns
t
LZ
Enable to Output C
L
=
10 pF, S2 Open 15 35 ns
t
HZ
Enable to Output C
L
=
10 pF, S1 Open 15 25 ns
t
ZL
Enable to Output C
L
=
30 pF, S2 Open 20 30 ns
t
ZH
Enable to Output C
L
=
30 pF, S1 Open 20 30 ns
Note 2: “Absolute Maximum Ratings” are those values beyond which the safety of the device cannot be guaranteed. They are not meant to imply that the devices
should be operated at these limits. The tables of “Electrical Characteristics” provide conditions for actual device operation.
Note 3: Unless otherwise specified min/max limits apply across the −55˚C to +125˚C temperature range for the DS726LS31M and across the 0˚C to +70˚C range
for the DS26LS31. All typicals are given for V
CC
=
5V and T
A
=
25˚C.
Note 4: All currents into device pins are positive; all currents out of device pins are negative. All voltages are referenced to ground unless otherwise specified.
Note 5: Only one output at a time should be shorted.
DS26LS31C/DS26LS31M
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AC Test Circuit and Switching Time Waveforms
Typical Applications
DS005778-3
S1 and S2 of load circuit are closed except where shown.
FIGURE 1. AC Test Circuit
DS005778-4
f=1 MHz, tr≤ 15 ns, tf≤ 6ns
FIGURE 2. Propagation Delays
DS005778-5
f=1 MHz, tr≤ 15 ns, tf≤ 6ns
FIGURE 3. Enable and Disable Times
Two-Wire Balanced System, RS-422
DS005778-6
Note 6: RTis optional although highly recommended to reduce reflection.
DS26LS31C/DS26LS31M
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