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DM74ALS257, DM74ALS258 3-STATE Quad 1-of-2-Line Data Selector/Multiplexer
May 2007
DM74ALS257, DM74ALS258
3-STATE Quad 1-of-2-Line Data Selector/Multiplexer
Features
■
Switching specifications at 50pF
■
Switching specifications guaranteed over full
■
■
■
■
■
■
■
■
tm
General Description
These data selectors/multiplexers contain inverters and
drivers to supply full on-chip data selection to the four
3-STATE outputs that can interface directly with data
lines of bus-organized systems. A 4-bit word selected
from one of two sources is routed to the four outputs.
The DM74ALS257 presents true data whereas the
DM74ALS258 presents inverted data to minimize propa-
gation delay time.
This 3-STATE output feature means that n-bit (paral-
leled) 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.
temperature and V
CC
range
Advanced oxide-isolated, ion-implanted Schottky TTL
process
Functionally and pin for pin compatible with Schottky
and low power Schottky TTL counterpart
Improved AC performance over Schottky and low
power Schottky counterparts
3-STATE buffer-type outputs drive bus lines directly
Expand any data input point
Multiplex dual data buses
General four functions of two variables (one variable
is common)
Source programmable counters
Ordering Information
Order Number
DM74ALS257M
DM74ALS257SJ
DM74ALS258M
Package
Number
M16A
M16D
M16A
Package Description
16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150" Narrow
16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150" Narrow
Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering number.
©1984 Fairchild Semiconductor Corporation
DM74ALS257, DM74ALS258 Rev. 1.2
www.fairchildsemi.com
DM74ALS257, DM74ALS258 3-STATE Quad 1-of-2-Line Data Selector/Multiplexer
Connection Diagram
Function Table
Inputs
Output Control
H
L
L
L
L
H
=
HIGH Level
L
=
LOW Level
X
=
Don't Care
Z
=
High Impedance (OFF)
Output Y
A
X
L
H
X
X
Select
X
L
L
H
H
B
X
X
X
L
H
DM74ALS257
Z
L
H
L
H
DM74ALS258
Z
H
L
H
L
©1984 Fairchild Semiconductor Corporation
DM74ALS257, DM74ALS258 Rev. 1.2
www.fairchildsemi.com
2
DM74ALS257, DM74ALS258 3-STATE Quad 1-of-2-Line Data Selector/Multiplexer
Logic Diagrams
DM74ALS257
DM74ALS258
©1984 Fairchild Semiconductor Corporation
DM74ALS257, DM74ALS258 Rev. 1.2
www.fairchildsemi.com
3
DM74ALS257, DM74ALS258 3-STATE Quad 1-of-2-Line Data Selector/Multiplexer
Absolute Maximum Ratings
Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be
operable above the recommended operating conditions and stressing the parts to these levels is not recommended.
In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability.
The absolute maximum ratings are stress ratings only.
Symbol
V
CC
V
I
T
A
T
STG
θ
JA
Supply Voltage
Input Voltage
Parameter
Rating
7V
7V
5.5V
0°C to +70°C
–65°C to +150°C
102.0°C/W
Voltage Applied to Disabled Output
Operating Free Air Temperature Range
Storage Temperature Range
Typical Thermal Resistance
Recommended Operating Conditions
The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended
operating conditions are specified to ensure optimal performance to the datasheet specifications. Fairchild does not
recommend exceeding them or designing to absolute maximum ratings.
Symbol
V
CC
V
IH
V
IL
I
OH
I
OL
T
A
Supply Voltage
Parameter
HIGH Level Input Voltage
LOW Level Input Voltage
HIGH Level Output Current
LOW Level Output Current
Free Air Operating Temperature
Min.
4.5
2
Nom.
5
Max.
5.5
0.8
–2.6
24
Units
V
V
V
mA
mA
°C
0
70
©1984 Fairchild Semiconductor Corporation
DM74ALS257, DM74ALS258 Rev. 1.2
www.fairchildsemi.com
4
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