NSC 54LS257ADMQB

54LS257A/DM54LS257B/DM74LS257B,
54LS258A/DM54LS258B/DM74LS258B
TRI-STATEÉ Quad 2-Data Selectors/Multiplexers
General Description
Features
These Schottky-clamped high-performance multiplexers
feature TRI-STATE outputs that can interface directly with
data lines of bus-organized systems. With all but one of the
common outputs disabled (at a high impedance state), the
low impedance of the single enabled output will drive the
bus line to a high or low logic level. To minimize the possibility that two outputs will attempt to take a common bus to
opposite logic levels, the output enable circuitry is designed
such that the output disable times are shorter than the output enable times.
This TRI-STATE output feature means that n-bit (paralleled)
data selectors with up to 258 sources can be implemented
for data buses. It also permits the use of standard TTL registers for data retention throughout the system.
Y
Y
Y
Y
Y
Y
TRI-STATE versions LS157 and LS158 with same pinouts
Schottky-clamped for significant improvement in A-C
performance
Provides bus interface from multiple sources in highperformance systems
Average propagation delay from data input 12 ns
Typical power dissipation
LS257B 50 mW
LS258B 35 mW
Alternate military/aerospace devices (54LS257A/
54LS258A) are available. Contact a National Semiconductor Sales Office/Distributor for specifications.
Connection Diagrams
Dual-In-Line Package
Dual-In-Line Package
TL/F/6417 – 2
TL/F/6417 – 1
Order Number 54LS258ADMQB, 54LS258AFMQB,
54LS258ALMQB, DM54LS258BJ, DM54LS258BW,
DM74LS258BM or DM74LS258BN
See NS Package Number E20A, J16A,
M16A, N16E or W16A
Order Number 54LS257ADMQB, 54LS257AFMQB,
54LS257ALMQB, DM54LS257BJ, DM54LS257BW,
DM74LS257BM or DM74LS257BN
See NS Package Number E20A, J16A,
M16A, N16E or W16A
Function Table
Inputs
Output Y
Output
Control
Select
A
B
LS257
LS258
H
L
L
L
L
X
L
L
H
H
X
L
H
X
X
X
X
X
L
H
Z
L
H
L
H
Z
H
L
H
L
H e High Level, L e Low Level, X e Don’t Care,
Z e High Impedance (off)
TRI-STATEÉ is a registered trademark of National Semiconductor Corporation.
C1995 National Semiconductor Corporation
TL/F/6417
RRD-B30M105/Printed in U. S. A.
54LS257A/DM54LS257B/DM74LS257B, 54LS258A/DM54LS258B/DM74LS258B
TRI-STATE Quad 2-Data Selectors/Multiplexers
June 1989
Absolute Maximum Ratings (Note)
Note: The ‘‘Absolute Maximum Ratings’’ are those values
beyond which the safety of the device cannot be guaranteed. The device should not be operated at these limits. The
parametric values defined in the ‘‘Electrical Characteristics’’
table are not guaranteed at the absolute maximum ratings.
The ‘‘Recommended Operating Conditions’’ table will define
the conditions for actual device operation.
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
Operating Free Air Temperature Range
b 55§ C to a 125§ C
DM54LS and 54LS
DM74LS
0§ C to a 70§ C
Storage Temperature Range
b 65§ C to a 150§ C
Recommended Operating Conditions
Symbol
DM54LS257B
Parameter
DM74LS257B
Units
Min
Nom
Max
Min
Nom
Max
4.5
5
5.5
4.75
5
5.25
VCC
Supply Voltage
VIH
High Level Input Voltage
VIL
Low Level Input Voltage
0.7
0.8
V
IOH
High Level Output Current
b1
b 2.6
mA
IOL
Low Level Output Current
24
mA
TA
Free Air Operating Temperature
70
§C
2
2
V
12
b 55
125
V
0
’LS257B Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted)
Symbol
Parameter
Min
Typ
(Note 1)
DM54
2.4
3.4
DM74
2.4
3.1
Conditions
Max
Units
b 1.5
V
VI
Input Clamp Voltage
VOH
High Level Output
Voltage
VCC e Min, II e b18 mA
VCC e Min, IOH e Max
VIL e Max, VIH e Min
Low Level Output
Voltage
VCC e Min, IOL e Max
VIL e Max, VIH e Min
DM54
0.25
DM74
0.35
0.5
IOL e 12 mA, VCC e Min
DM74
0.25
0.4
Input Current @ Max
Input Voltage
VCC e Max,
VI e 7V
Select
0.2
Other
0.1
High Level Input
Current
VCC e Max,
VI e 2.7V
Select
40
Other
20
Low Level Input
Current
VCC e Max,
VI e 0.4V
Select
b 0.8
Other
b 0.4
Off-State Output Current
with High Level Output
Voltage Applied
VCC e Max, VO e 2.7V
VIH e Min, VIL e Max
20
mA
Off-State Output Current
with Low Level Output
Voltage Applied
VCC e Max, VO e 0.4V
VIH e Min, VIL e Max
b 20
mA
Short Circuit
Output Current
VCC e Max
(Note 2)
ICCH
Supply Current with
Outputs High
VCC e Max (Note 3)
5.9
10
mA
ICCL
Supply Current with
Outputs Low
VCC e Max (Note 3)
9.2
16
mA
ICCZ
Supply Current with
Outputs Disabled
VCC e Max (Note 3)
12
19
mA
VOL
II
IIH
IIL
IOZH
IOZL
IOS
0.4
DM54
b 20
b 100
DM74
b 20
b 100
Note 1: All typicals are at VCC e 5V, TA e 25§ C.
Note 2: Not more than one output should be shorted at a time, and the duration should not exceed one second.
Note 3: ICC is measured with all outputs open and all possible inputs grounded, while achieving the stated output conditions.
2
V
V
mA
mA
mA
mA
’LS257B Switching Characteristics
at VCC e 5V and TA e 25§ C (See Section 1 for Test Waveforms and Output Load)
Symbol
RL e 667X
From (Input)
To (Output)
Parameter
CL e 45 pF
Min
CL e 150 pF
Max
Min
Units
Max
tPLH
Propagation Delay Time
Low to High Level Output
Data to
Output
18
27
ns
tPHL
Propagation Delay Time
High to Low Level Output
Data to
Output
18
27
ns
tPLH
Propagation Delay Time
Low to High Level Output
Select to
Output
28
35
ns
tPHL
Propagation Delay Time
High to Low Level Output
Select to
Output
35
42
ns
tPZH
Output Enable Time
to High Level Output
Output
Control to Y
15
27
ns
tPZL
Output Enable Time
to Low Level Output
Output
Control to Y
28
38
ns
tPHZ
Output Disable Time from
High Level Output (Note 1)
Output
Control to Y
26
ns
tPLZ
Output Disable Time from
Low Level Output (Note 1)
Output
Control to Y
25
ns
Note 1: CL e 5 pF.
Recommended Operating Conditions
Symbol
DM54LS258B
Parameter
DM74LS258B
Units
Min
Nom
Max
Min
Nom
Max
4.5
5
5.5
4.75
5
5.25
VCC
Supply Voltage
VIH
High Level Input Voltage
VIL
Low Level Input Voltage
0.7
0.8
V
IOH
High Level Output Current
b1
b 2.6
mA
IOL
Low Level Output Current
12
24
mA
70
§C
Max
Units
b 1.5
V
TA
2
Free Air Operating Temperature
2
b 55
125
V
V
0
’LS258B Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted)
Symbol
VI
VOH
VOL
II
IIH
Parameter
Conditions
Min
Typ
(Note 1)
Input Clamp Voltage
VCC e Min, II e b18 mA
High Level Output
Voltage
VCC e Min, IOH e Max
VIL e Max, VIH e Min
DM54
2.4
3.4
DM74
2.4
3.1
Low Level Output
Voltage
VCC e Min, IOL e Max
VIL e Max, VIH e Min
DM54
0.25
0.4
DM74
0.35
0.5
IOL e 12 mA, VCC e Min
DM74
0.25
0.4
Input Current @ Max
Input Voltage
VCC e Max,
VI e 7V
Select
0.2
Other
0.1
High Level Input
Current
VCC e Max,
VI e 2.7V
Select
40
Other
20
3
V
V
mA
mA
’LS258B Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted) (Continued)
Symbol
IIL
Parameter
Conditions
Min
Typ
(Note 1)
Max
Low Level Input
Current
VCC e Max,
VI e 0.4V
Off-State Output Current
with High Level Output
Voltage Applied
VCC e Max, VO e 2.7V
VIH e Min, VIL e Max
20
mA
Off-State Output Current
with Low Level Output
Voltage Applied
VCC e Max, VO e 0.4V
VIH e Min, VIL e Max
b 20
mA
Short Circuit
Output Current
VCC e Max
(Note 2)
ICCH
Supply Current with
Outputs High
VCC e Max (Note 3)
4.1
7
mA
ICCL
Supply Current with
Outputs Low
VCC e Max (Note 3)
9
14
mA
ICCZ
Supply Current with
Outputs Disabled
VCC e Max (Note 3)
12
19
mA
IOZH
IOZL
IOS
Select
b 0.8
Other
b 0.4
Units
DM54
b 20
b 100
DM74
b 20
b 100
mA
mA
Note 1: All typicals are at VCC e 5V, TA e 25§ C.
Note 2: Not more than one output should be shorted at a time, and the duration should not exceed one second.
Note 3: ICC is measured with all outputs open and all possible inputs grounded, while achieving the stated output conditions.
’LS258B Switching Characteristics
at VCC e 5V and TA e 25§ C (See Section 1 for Test Waveforms and Output Load)
Symbol
Parameter
RL e 667X
From (Input)
To (Output)
CL e 45 pF
Min
Max
CL e 150 pF
Min
Units
Max
tPLH
Propagation Delay Time
Low to High Level Output
Data to
Output
18
27
ns
tPHL
Propagation Delay Time
High to Low Level Output
Data to
Output
18
27
ns
tPLH
Propagation Delay Time
Low to High Level Output
Select to
Output
28
35
ns
tPHL
Propagation Delay Time
High to Low Level Output
Select to
Output
35
42
ns
tPZH
Output Enable Time
to High Level Output
Output
Control to Y
15
27
ns
tPZL
Output Enable Time
to Low Level Output
Output
Control to Y
28
38
ns
tPHZ
Output Disable Time from
High Level Output (Note 4)
Output
Control to Y
26
ns
tPLZ
Output Disable Time from
Low Level Output (Note 4)
Output
Control to Y
25
ns
Note 4: CL e 5 pF.
4
Logic Diagrams
LS257B
TL/F/6417 – 3
LS258B
TL/F/6417 – 4
5
Physical Dimensions inches (millimeters)
Ceramic Leadless Chip Carrier Package (E)
Order Number 54LS257ALMQB or 54LS258ALMQB
NS Package Number E20A
16-Lead Ceramic Dual-In-Line Package (J)
Order Number 54LS257ADMQB, 54LS258ADMQB, DM54LS257BJ or DM54LS258BJ
NS Package Number J16A
6
Physical Dimensions inches (millimeters) (Continued)
16-Lead Small Outline Molded Package (M)
Order Number DM74LS257BM or DM74LS258BM
NS Package Number M16A
16-Lead Molded Dual-In-Line Package (N)
Order Number DM74LS257BN or DM74LS258BN
NS Package Number N16E
7
54LS257A/DM54LS257B/DM74LS257B, 54LS258A/DM54LS258B/DM74LS258B
TRI-STATE Quad 2-Data Selectors/Multiplexers
Physical Dimensions inches (millimeters) (Continued)
16-Lead Ceramic Flat Package (W)
Order Number 54LS257AFMQB or 54LS258AFMQB
NS Package Number W16A
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