DS26LS31C/DS26LS31M
Quad High Speed Differential Line Driver
DS26LS31C/DS26LS31M Quad High Speed Differential Line Driver
June 1998
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 RS422 and Federal 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.
Logic and Connection Diagrams
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
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
CC
00577801
=0V
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
TRI-STATE®is a registered trademark of National Semiconductor Corporation.
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
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
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.
Input to OutputCL=30pF1015ns
Input to OutputCL=30pF1015ns
= 30 pF2.06.0ns
L
Enable to OutputCL= 10 pF, S2 Open1535ns
Enable to OutputCL= 10 pF, S1 Open1525ns
Enable to OutputCL= 30 pF, S2 Open2030ns
Enable to OutputCL= 30 pF, S1 Open2030ns
= 5V and TA= 25˚C.
CC
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Page 3
AC Test Circuit and Switching Time Waveforms
DS26LS31C/DS26LS31M
S1 and S2 of load circuit are closed except where shown.
f = 1 MHz, tr≤ 15 ns, tf≤ 6ns
00577803
FIGURE 1. AC Test Circuit
00577804
FIGURE 2. Propagation Delays
f = 1 MHz, tr≤ 15 ns, tf≤ 6ns
00577805
FIGURE 3. Enable and Disable Times
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Page 4
Typical Applications
Two-Wire Balanced System, RS-422
DS26LS31C/DS26LS31M
Note 6: RTis optional although highly recommended to reduce reflection.
DS26LS31C/DS26LS31M Quad High Speed Differential Line Driver
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DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL
COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein:
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whose failure to perform when properly used in
accordance with instructions for use provided in the
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support device or system whose failure to perform
can be reasonably expected to cause the failure of
the life support device or system, or to affect its
safety or effectiveness.
labeling, can be reasonably expected to result in a
significant injury to the user.
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Stewardship Specification (CSP-9-111C2) and the Banned Substances and Materials of Interest Specification
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National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.
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