© 2000 Fairchild Semiconductor Corporation
DS006227
www.fairchildsemi.com
April 1984
Revised February 2000
DM74ALS257
·
DM74ALS258 3-
ST
A
T
E Q
u
a
d
1-
of-
2
-Li
ne Data Sele
ctor
/Mult
i
p
lexer
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:
Devices also available in Tape and Reel. Specify by appending the suffix letter "X" to the ordering code.
Connection Diagram
Function Table
H
=
HIGH Level
L
=
LOW Level
X
=
Don't Care
Z
=
High Impedance (OFF)
Order Number
Package Number
Package Description
DM74ALS257M
M16A
16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow
DM74ALS257SJ
M16D
16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
DM74ALS257N
N16E
16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
DM74ALS258M
M16A
16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow
DM74ALS258N
N16E
16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Inputs
Output Y
Output
Select
A
B
DM74ALS257 DM74ALS258
Control
H
X
X
X
Z
Z
L
L
L
X
L
H
L
L
H
X
H
L
L
H
X
L
L
H
L
H
X
H
H
L
3
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DM74ALS257
· DM74ALS258
Absolute Maximum Ratings
(Note 1)
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
Electrical Characteristics
over recommended operating free air temperature range. All typical values are measured at V
CC
=
5V, T
A
=
25
°
C.
Supply Voltage
7V
Input Voltage
7V
Voltage Applied to Disabled Output
5.5V
Operating Free Air Temperature Range
0
°
C to
+
70
°
C
Storage Temperature Range
-
65
°
C to
+
150
°
C
Typical
JA
N Package
73.0
°
C/W
M Package
102.0
°
C/W
Symbol
Parameter
Min
Nom
Max
Units
V
CC
Supply Voltage
4.5
5
5.5
V
V
IH
HIGH Level Input Voltage
2
V
V
IL
LOW Level Input Voltage
0.8
V
I
OH
HIGH Level Output Current
-
2.6
mA
I
OL
LOW Level Output Current
24
mA
T
A
Free Air Operating Temperature
0
70
°
C
Symbol
Parameter
Conditions
Min
Typ
Max
Units
V
IK
Input Clamp Voltage
V
CC
=
4.5V, I
I
=
-
18 mA
-
1.5
V
V
OH
HIGH Level
V
CC
=
4.5V
I
OH
=
-
2.6 mA
2.4
3.3
V
Output Voltage
I
OH
=
-
0.4 mA
V
CC
-
2
V
V
OL
LOW Level
V
CC
=
4.5V
I
OL
=
12 mA
0.25
0.4
V
Output Voltage
I
OL
=
24 mA
0.35
0.5
V
I
I
Input Current at Maximum
V
CC
=
5.5V, V
IH
=
7V
0.1
mA
Input Voltage
I
IH
HIGH Level Input Current
V
CC
=
5.5V, V
IH
=
2.7V
20
µ
A
I
IL
LOW Level Input Current
V
CC
=
5.5V, V
IL
=
0.4V
-
0.1
mA
I
O
Output Drive Current
V
CC
=
5.5V, V
O
=
2.25V
-
30
-
112
mA
I
OZH
OFF-State Output Current
V
CC
=
5.5V,
20
µ
A
HIGH Level Voltage Applied
V
O
=
2.7V
I
OZL
OFF-State Output Current,
V
CC
=
5.5V,
-
20
µ
A
LOW Level Voltage Applied
V
O
=
0.4V
I
CCH
Supply
DM74ALS257 V
CC
=
5.5V
Outputs HIGH
3
6
mA
Current
DM74ALS258 Outputs OPEN
2.5
4
mA
I
CCL
Supply
DM74ALS257
Outputs LOW
8
12
mA
Current
DM74ALS258
7
11
mA
I
CCZ
Supply
DM74ALS257
Outputs Disabled
9
14
mA
Current
DM74ALS258
8
13
mA
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4
D
M
74ALS257
· D
M
74ALS258
Switching Characteristics DM74ALS257
over recommended operating free air temperature range
Switching Characteristics DM74ALS258
over recommended operating free air temperature range
Symbol
Parameter
Conditions
From
To
Min
Max
Units
t
PLH
Propagation Delay Time
V
CC
=
4.5V to 5.5V
Data
Any Y
2
10
ns
LOW-to-HIGH Level Output
C
L
=
50 pF
t
PHL
Propagation Delay Time
R
L
=
500
Data
Any Y
2
12
ns
HIGH-to-LOW Level Output
t
PLH
Propagation Delay Time
Select
Any Y
4
18
ns
LOW-to-HIGH Level Output
t
PHL
Propagation Delay Time
Select
Any Y
5
22
ns
HIGH-to-LOW Level Output
t
ZH
Output Enable Time
Output
Any Y
4
16
ns
to HIGH Level
Control
t
ZL
Output Enable Time
Output
Any Y
5
18
ns
to LOW Level
Control
t
HZ
Output Disable Time
Output
Any Y
2
10
ns
from HIGH Level
Control
t
LZ
Output Disable Time
Output
Any Y
3
15
ns
from LOW Level
Control
Symbol
Parameter
Conditions
From
To
Min
Max
Units
t
PLH
Propagation Delay Time
V
CC
=
4.5V to 5.5V
Data
Any Y
2
8
ns
LOW-to-HIGH Level Output
C
L
=
50 pF
t
PHL
Propagation Delay Time
R
L
=
500
Data
Any Y
2
7
ns
HIGH-to-LOW Level Output
t
PLH
Propagation Delay Time
Select
Any Y
3
20
ns
LOW-to-HIGH Level Output
t
PHL
Propagation Delay Time
Select
Any Y
5
25
ns
HIGH-to-LOW Level Output
t
ZH
Output Enable Time
Output
Any Y
5
18
ns
to HIGH Level
Control
t
ZL
Output Enable Time
Output
Any Y
5
18
ns
to LOW Level
Control
t
HZ
Output Disable Time
Output
Any Y
2
10
ns
from HIGH Level
Control
t
LZ
Output Disable Time
Output
Any Y
3
18
ns
from LOW Level
Control
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