DM74ALS257 • DM74ALS258 3-STATE Quad 1-of-2-Line Data Selector/Multiplexer
April 1984
Revised February 2000
DM74ALS257 • DM74ALS258
3-STATE Quad 1-of-2-Line Data Selector/Multiplexer
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 propaga-
tion delay time.
This 3-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 reg-
isters for data retention throughout the system.
Features
s
Switching specifications at 50 pF
s
Switching specifications guaranteed over full tempera-
ture and V
CC
range
s
Advanced oxide-isolated, ion-implanted Schottky TTL
process
s
Functionally and pin for pin compatible with Schottky
and low power Schottky TTL counterpart
s
Improved AC performance over Schottky and low power
Schottky counterparts
s
3-STATE buffer-type outputs drive bus lines directly
s
Expand any data input point
s
Multiplex dual data buses
s
General four functions of two variables (one variable is
common)
s
Source programmable counters
Ordering Code:
Order Number
DM74ALS257M
DM74ALS257SJ
DM74ALS257N
DM74ALS258M
DM74ALS258N
Package Number
M16A
M16D
N16E
M16A
N16E
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 Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow
16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Connection Diagram
Function Table
Inputs
Output
Control
H
L
L
L
L
Select
X
L
L
H
H
A
X
L
H
X
X
B
X
X
X
L
H
Output Y
DM74ALS257 DM74ALS258
Z
L
H
L
H
Z
H
L
H
L
H
=
HIGH Level
L
=
LOW Level
X
=
Don't Care
Z
=
High Impedance (OFF)
© 2000 Fairchild Semiconductor Corporation
DS006227
www.fairchildsemi.com
DM74ALS257 • DM74ALS258
Absolute Maximum Ratings
(Note 1)
Supply Voltage
Input Voltage
Voltage Applied to Disabled Output
Operating Free Air Temperature Range
Storage Temperature Range
Typical
θ
JA
N Package
M Package
73.0°C/W
102.0°C/W
7V
7V
5.5V
0°C to
+70°C
−65°C
to
+150°C
Note 1:
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 tables are not guaranteed at the absolute maximum ratings.
The “Recommended Operating Conditions” table will define the conditions
for actual device operation.
Recommended Operating Conditions
Symbol
V
CC
V
IH
V
IL
I
OH
I
OL
T
A
Supply Voltage
HIGH Level Input Voltage
LOW Level Input Voltage
HIGH Level Output Current
LOW Level Output Current
Free Air Operating Temperature
0
Parameter
Min
4.5
2
0.8
−2.6
24
70
Nom
5
Max
5.5
Units
V
V
V
mA
mA
°C
Electrical Characteristics
over recommended operating free air temperature range. All typical values are measured at V
CC
=
5V, T
A
=
25°C.
Symbol
V
IK
V
OH
V
OL
I
I
I
IH
I
IL
I
O
I
OZH
I
OZL
I
CCH
I
CCL
I
CCZ
Parameter
Input Clamp Voltage
HIGH Level
Output Voltage
LOW Level
Output Voltage
Input Current at Maximum
Input Voltage
HIGH Level Input Current
LOW Level Input Current
Output Drive Current
OFF-State Output Current
HIGH Level Voltage Applied
OFF-State Output Current,
LOW Level Voltage Applied
Supply
Current
Supply
Current
Supply
Current
V
CC
=
5.5V, V
IH
=
7V
V
CC
=
5.5V, V
IH
=
2.7V
V
CC
=
5.5V, V
IL
=
0.4V
V
CC
=
5.5V, V
O
=
2.25V
V
CC
=
5.5V,
V
O
=
2.7V
V
CC
=
5.5V,
V
O
=
0.4V
Outputs HIGH
Outputs LOW
Outputs Disabled
3
2.5
8
7
9
8
DM74ALS257 V
CC
=
5.5V
DM74ALS258 Outputs OPEN
DM74ALS257
DM74ALS258
DM74ALS257
DM74ALS258
−30
V
CC
=
4.5V
I
OH
= −0.4
mA
V
CC
=
4.5V
I
OL
=
12 mA
I
OL
=
24 mA
Conditions
V
CC
=
4.5V, I
I
= −18
mA
I
OH
= −2.6
mA
2.4
V
CC
−
2
0.25
0.35
0.4
0.5
0.1
20
−0.1
−112
20
−20
6
4
12
11
14
13
3.3
Min
Typ
Max
−1.5
Units
V
V
V
V
V
mA
µA
mA
mA
µA
µA
mA
mA
mA
mA
mA
mA
3
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