Fairchild DM74AS257 3-state quad 1 of 2 line data selector/multiplexer Datasheet

Revised March 2000
DM74AS257 • DM74AS258
3-STATE Quad 1 of 2 Line Data Selector/Multiplexers
General Description
Features
These data selectors/multiplexers contain inverters and
drivers to supply full on-chip data selection to the four 3STATE 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 DM74AS257
presents true data whereas the DM74AS258 presents
inverted data to minimize propagation delay time.
■ Switching specifications at 50 pF
This 3-STATE output feature means that n-bit (paralleled)
data selectors with up to 300 sources can be implemented
for data buses. It also permits the use of standard TTL registers for data retention throughout the system.
■ Switching specifications guaranteed over full temperature and VCC range
■ Advanced oxide-isolated, ion-implanted Schottky TTL
process
■ Functionally and pin for pin compatible with Schottky,
low power Schottky, and advanced low power Schottky
TTL counterpart
■ Improved AC performance over Schottky, low power
Schottky, and advanced low power Schottky counterparts
■ 3-STATE buffer-type output 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 Code:
Order Number
DM74AS257M
Package Number
Package Description
M16A
16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow
DM74AS257N
N16E
16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
DM74AS258M
M16A
16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow
DM74AS258N
N16E
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 Y
OUTPUT
SELECT
A
B
AS257
AS258
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
CONTROL
H = HIGH Level
L = LOW Level
X = Don't Care
Z = High Impedance (OFF)
© 2000 Fairchild Semiconductor Corporation
DS006107
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DM74AS257 • DM74AS258 3-STATE Quad 1 of 2 Line Data Selector/Multiplexers
September 1986
DM74AS257 • DM74AS258
Logic Diagrams
DM74AS257
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DM74AS258
2
Supply Voltage, VCC
7V
Input Voltage
7V
Voltage Applied to Disabled Output
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.
5.5V
0°C to +70°C
Operating Free Air Temperature Range
−65°C to +150°C
Storage Temperature Range
Typical θJA
N Package
75.0°C/W
Recommended Operating Conditions
Symbol
Parameter
Min
Nom
Max
4.5
5
5.5
Units
VCC
Supply Voltage
VIH
HIGH Level Input Voltage
V
VIL
LOW Level Input Voltage
0.8
V
IOH
HIGH Level Output Current
−15
mA
IOL
LOW Level Output Current
48
mA
TA
Free Air Operating Temperature
70
°C
2
V
0
Electrical Characteristics
over recommended operating free air temperature range. All typical values are measured at VCC = 5V, TA = 25°C.
Symbol
VIK
Parameter
Input Clamp
VOL
HIGH Level
VCC = 4.5V, IOH = Max
Output Voltage
IOH = −2 mA, VCC = 4.5V to 5.5V
LOW Level
Output Voltage
II
Input Current @
2.4
VCC = 5.5V, VIH = 7V
VCC = 5.5V, VIH = 2.7V
HIGH Level
VCC = 5.5V, VIL = 0.4V
LOW Level
Output Drive Current
VCC = 5.5V, VO = 2.25V
IOZH
Off-State Output Current,
VCC = 5.5V
HIGH Level Voltage Applied
VO = 2.7V
IOZL
ICCH
ICCL
ICCZ
Off-State Output Current,
VCC = 5.5V
LOW Level Voltage Applied
VO = 0.4V
Supply
DM74AS257
Current
DM74AS258
Supply
DM74AS257
VCC = 5.5V
Current
DM74AS258
Outputs Open
Supply
DM74AS257
Current
DM74AS258
−1.2
V
V
0.5
A, B, G
0.1
Select
0.2
A, B, G
20
Select
40
−1
−0.5
All Others
IO (Note 2)
Units
V
Select
Input Current
Max
3.2
0.35
Input Current
IIL
Typ
VCC − 2
VCC = 4.5V, IOL = Max
Max Input Voltage
IIH
Min
VCC = 4.5V, II = −18 mA
Voltage
VOH
Conditions
−30
Outputs HIGH
Outputs LOW
Outputs Disabled
V
mA
µA
mA
−112
mA
−50
µA
−50
µA
12.9
19.7
mA
8.8
13.5
mA
19
30.6
mA
15.8
24.6
mA
19.7
31.9
mA
15.5
25.2
mA
Note 2: The output conditions have been chosen to produce a current that closely approximates one half of the true short-circuit output current, IOS.
3
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DM74AS257 • DM74AS258
Absolute Maximum Ratings(Note 1)
DM74AS257 • DM74AS258
DM74AS257 Switching Characteristics
over recommended operating free air temperature range
Symbol
tPLH
Parameter
From
To
Data
Any
Propagation Delay Time,
LOW-to-HIGH Level Output
tPHL
Conditions
VCC = 4.5V to 5.5V,
CL = 50 pF,
Y
RL = 500Ω
Propagation Delay Time,
HIGH-to-LOW Level Output
tPLH
Propagation Delay Time,
Select
LOW-to-HIGH Level Output
tPHL
Any
Y
Propagation Delay Time,
HIGH-to-LOW Level Output
tPZH
Output Enable Time to
HIGH Level
tPZL
OUTPUT
Any
Control
Y
Output Enable Time to
LOW Level
tPHZ
Output Disable Time,
from HIGH Level
tPLZ
OUTPUT
Any
Control
Y
Output Disable Time,
from LOW Level
Min
Max
Units
1
5.5
ns
1
6
ns
2
11
ns
2
10
ns
2
7.5
ns
2
9.5
ns
1.5
6.5
ns
2
7
ns
Min
Max
Units
1
5
ns
1
4
ns
2
9.5
ns
2
10
ns
2
8
ns
2
10
ns
1.5
6
ns
2
6.5
ns
DM74AS258 Switching Characteristics
over recommended operating free air temperature range
Symbol
tPLH
Parameter
Propagation Delay Time,
From
To
Data
Any
LOW-to-HIGH Level Output
tPHL
Conditions
CL = 50 pF,
Y
RL = 500Ω
Propagation Delay Time,
HIGH-to-LOW Level Output
tPLH
Propagation Delay Time,
Select
LOW-to-HIGH Level Output
tPHL
Any
Y
Propagation Delay Time,
HIGH-to-LOW Level Output
tPZH
Output Enable Time to
HIGH Level
tPZL
OUTPUT
Any
Control
Y
Output Enable Time to
LOW Level
tPHZ
Output Disable Time,
from HIGH Level
tPLZ
OUTPUT
Any
Control
Y
Output Disable Time,
from LOW Level
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VCC = 4.5V to 5.5V,
4
DM74AS257 • DM74AS258
Physical Dimensions inches (millimeters) unless otherwise noted
16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow
Package Number M16A
5
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DM74AS257 • DM74AS258 3-STATE Quad 1 of 2 Line Data Selector/Multiplexers
Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Package Number N16E
Fairchild does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and
Fairchild reserves the right at any time without notice to change said circuitry and specifications.
LIFE SUPPORT POLICY
FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD
SEMICONDUCTOR CORPORATION. As used herein:
2. A critical component in any component of a life support
device or system whose failure to perform can be reasonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the
body, or (b) support or sustain life, and (c) whose failure
to perform when properly used in accordance with
instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the
user.
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6
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