National Semiconductor DS26C31T, DS26C31M Technical data
DS26C31T/DS26C31M
CMOS Quad TRI-STATE
®
Differential Line Driver
DS26C31T/DS26C31M CMOS Quad TRI-STATE Differential Line Driver
June 1998
General Description
The DS26C31 is a quad differential line driver designed for
digital data transmission over balanced lines. The
DS26C31T meets all the requirements of EIA standard RS422 while retaining the low power characteristics of CMOS.
The DS26C31M is compatible with EIA standard RS-422;
however, one exception in test methodology is taken (Note
8). This enables the construction of serial and terminal interfaces while maintaining minimal power consumption.
The DS26C31 accepts TTL or CMOS input levels and translates these to RS-422 output levels. This part uses special
output circuitry that enables the drivers to power down without loading down the bus. This device has enable and disable circuitry common to all four drivers. The DS26C31 is pin
compatible to the AM26LS31 and the DS26LS31.
All inputs are protected against damage due to electrostatic
discharge by diodes to V
and ground.
CC
Connection Diagrams
Dual-In-Line Package
Features
n TTL input compatible
n Typical propagation delays: 6 ns
n Typical output skew: 0.5 ns
n Outputs will not load line when V
n DS26C31T meets the requirements of EIA standard
RS-422
n Operation from single 5V supply
n TRI-STATE outputs for connection to system buses
n Low quiescent current
n Available in surface mount
n Mil-Std-883C compliant
20-Lead Ceramic Leadless Chip Carrier (E)
CC
=0V
Top View
Order Number DS26C31TM or DS26C31TN
See NS Package Number M16A or N16E
For Complete Military Product Specifications,
refer to the appropriate SMD or MDS.
Order Number DS26C31ME/883, DS26C31MJ/883
or DS26C31MW/883
See NS Package Number E20A, J16A or W16A
TRI-STATE®is a registered trademark of National Semiconductor Corporation.
™
FACT
is a trademark of National Semiconductor Corporation.
© 2004 National Semiconductor Corporation DS008574 www.national.com
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Truth Table
ENABLE ENABLE Input Non-Inverting Inverting
Output Output
LHX Z Z
All other L L H
combinations of H H L
enable inputs
L = Low logic state
X = Irrelevant
H = High logic state
Z = TRI-STATE (high impedance)
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Absolute Maximum Ratings (Notes 1,
2)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage (V
DC Input Voltage (V
DS26C31T/DS26C31M
DC Output Voltage (V
Clamp Diode Current (I
DC Output Current, per pin (I
DC V
or GND Current,
CC
per pin (I
CC
Storage Temperature Range (T
Max. Power Dissipation (P
Ceramic “J” Pkg. 2419 mW
Plastic “N” Pkg. 1736 mW
) −0.5V to 7.0V
CC
) −1.5V to V
IN
) −0.5V to 7V
OUT
)
IK,IOK
)
OUT
)
) −65˚C to +150˚C
STG
)@25˚C (Note 3)
D
+1.5V
±
20 mA
±
150 mA
±
150 mA
CC
SOIC “M” Pkg. 1226 mW
Ceramic “W” Pkg. 1182 mW
Ceramic “E” Pkg. 2134 mW
Lead Temperature (T
)
L
(Soldering, 4 sec.) 260˚C
This device does not meet 2000V ESD Rating. (Note 13)
Operating Conditions
Min Max Units
Supply Voltage (V
DC Input or Output Voltage
(V
IN,VOUT
Operating Temperature Range (T
DS26C31T −40 +85 ˚C
DS26C31M −55 +125 ˚C
Input Rise or Fall Times (t
) 4.50 5.50 V
CC
)0V
)
A
) 500 ns
r,tf
DC Electrical Characteristics
VCC=5V±10% (unless otherwise specified) (Note 4)
Symbol Parameter Conditions Min Typ Max Units
V
IH
V
IL
V
OH
V
OL
V
T
|V
|−|VT| Difference In RL= 100Ω 0.4 V
T
V
OS
|V
OS−VOS
I
IN
I
CC
I
OZ
I
SC
I
OFF
High Level Input Voltage 2.0 V
Low Level Input Voltage 0.8 V
High Level Output Voltage VIN=VIHor VIL, 2.5 3.4 V
I
= −20 mA
OUT
Low Level Output VIN=VIHor VIL, 0.3 0.5 V
Voltage I
OUT
=20mA
Differential Output RL= 100Ω 2.0 3.1 V
Voltage (Note 5)
Differential Output (Note 5)
Common Mode RL= 100Ω 1.8 3.0 V
Output Voltage (Note 5)
| Difference In RL= 100Ω 0.4 V
Common Mode Output (Note 5)
Input Current VIN=VCC, GND, VIH,orV
IL
Quiescent Supply DS26C31T VIN=VCCor GND 200 500 µA
Current (Note 6) I
=0µA VIN= 2.4V or 0.5V 0.8 2.0 mA
OUT
(Note 6)
DS26C31M V
I
=0µA VIN= 2.4V or 0.5V 0.8 2.1 mA
OUT
IN=VCC
or GND 200 500 µA
(Note 6)
TRI-STATE Output V
OUT=VCC
Leakage Current ENABLE = V
ENABLE = V
or GND
IL
IH
±
0.5
Output Short VIN=VCCor GND −30 −150 mA
Circuit Current (Notes 5, 7)
Output Leakage Current DS26C31T V
Power Off (Note 5) V
=0V V
CC
DS26C31M V
V
=0V V
CC
= 6V 100 µA
OUT
= −0.25V −100 µA
OUT
= 6V 100 µA
OUT
= 0V −100 µA
OUT
(Note 8)
CC
±
1.0 µA
±
5.0 µA
V
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DC Electrical Characteristics (Continued)
Note 1: Absolute Maximum Ratings are those values beyond which the safety of the device cannot be guaranteed. They are not meant to imply that the device
should be operated at these limits. The table of “Electrical Characteristics” provide conditions for actual device operation.
Note 2: Unless otherwise specified, all voltages are referenced to ground. All currents into device pins are positive, all currents out of device pins are negative.
Note 3: Ratings apply to ambient temperature at 25˚C. Above this temperature derate N package at 13.89 mW/˚C, J package 16.13 mW/˚C, M package
9.80 mW/˚C, E package 12.20 mW/˚C, and W package 6.75 mW/˚C.
Note 4: Unless otherwise specified, min/max limits apply across the recommended operating temperature range.All typicals are given for V
Note 5: See EIA Specification RS-422 for exact test conditions.
Note 6: Measured per input. All other inputs at V
Note 7: This is the current sourced when a high output is shorted to ground. Only one output at a time should be shorted.
Note 8: The DS26C31M (−55˚C to +125˚C) is tested with V
CC
or GND.
between +6V and 0V while RS-422A condition is +6V and −0.25V.
OUT
= 5V and TA= 25˚C.
CC
Switching Characteristics
VCC=5V±10%, tr≤ 6 ns, tf≤ 6ns(Figures 1, 2, 3, 4) (Note 4)
Symbol Parameter Conditions Min Typ Max Units
DS26C31T CS26C31M
t
PLH,tPHL
Skew (Note 9) S1 Open 0.5 2.0 3.0 ns
t
TLH,tTHL
t
PZH
t
PZL
t
PHZ
t
PLZ
C
PD
C
IN
Note 9: Skew is defined as the difference in propagation delays between complementary outputs at the 50% point.
Note 10: Output disable time is the delay from ENABLE or ENABLE being switched to the output transistors turning off. The actual disable times are less than
indicated due to the delay added by the RC time constant of the load.
Note 11: C
I
.
CC
Propagation Delays S1 Open 2 6 11 14 ns
Input to Output
Differential Output Rise S1 Open 6 10 14 ns
And Fall Times
Output Enable Time S1 Closed 11 19 22 ns
Output Enable Time S1 Closed 13 21 28 ns
Output Disable Time S1 Closed 5 9 12 ns
(Note 10)
Output Disable Time S1 Closed 7 11 14 ns
(Note 10)
Power Dissipation 50 pF
Capacitance (Note 11)
Input Capacitance 6 pF
determines the no load dynamic power consumption, PD=CPDVCC2f+ICCVCC, and the no load dynamic current consumption, IS=CPDVCCf+
PD
DS26C31T/DS26C31M
Comparison Table of Switching Characteristics into “LS-Type” Load
VCC= 5V, TA= 25˚C, tr≤ 6 ns, tf≤ 6ns(Figures 2, 4, 5, 6) (Note 12)
Symbol Parameter Conditions DS26C31T DS26LS31C Units
Typ Max Typ Max
t
PLH,tPHL
Skew (Note 9) C
t
THL,tTLH
t
PLZ
Propagation Delays CL=30pF
Input to Output S1 Closed 6 8 10 15 ns
S2 Closed
=30pF
L
S1 Closed 0.5 1.0 2.0 6.0 ns
S2 Closed
Differential Output Rise CL=30pF
and Fall Times S1 Closed 4 6 ns
S2 Closed
Output Disable Time CL=10pF
(Note 10) S1 Closed 6 9 15 35 ns
S2 Open
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Comparison Table of Switching Characteristics into “LS-Type”
Load
VCC= 5V, TA= 25˚C, tr≤ 6 ns, tf≤ 6ns(Figures 2, 4, 5, 6) (Note 12)
t
PHZ
DS26C31T/DS26C31M
t
PZL
t
PZH
Note 12: This table is provided for comparison purposes only. The values in this table for the DS26C31 reflect the performance of the device but are not tested or
guaranteed.
Note 13: ESD Rating:
(Continued)
Symbol Parameter Conditions DS26C31T DS26LS31C Units
Typ Max Typ Max
Output Disable Time CL=10pF
(Note 10) S1 Open 4 7 15 25 ns
S2 Closed
Output Enable Time CL=30pF
S1 Closed 14 20 20 30 ns
S2 Open
Output Enable Time CL=30pF
S1 Open 11 17 20 30 ns
S2 Closed
HBM (1.5 kΩ, 100 pF)
Inputs ≥ 1500V
Outputs ≥ 1000V
EIAJ (0Ω, 200 pF) ≥ 350V
Logic Diagram
AC Test Circuit and Switching Time Waveforms
Note: C1 = C2 = C3 = 40 pF (Including Probe and Jig Capacitance), R1 = R2 = 50Ω,R3=500Ω.
FIGURE 1. AC Test Circuit
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