DM74LS157/DM74LS158
Quad 2-Line to 1-Line Data Selectors/Multiplexers
General Description
These data selectors/multiplexers contain inverters and driv-
ers to supply full on-chip data selection to the four output
gates.Aseparate strobe input is provided.A4-bit word is se-
lected from one of two sources and is routed to the four out-
puts. The LS157 presents true data whereas the LS158 pre-
sents inverted data to minimize propagation delay time.
Applications
nExpand any data input point
nMultiplex dual data buses
nGenerate four functions of two variables (one variable is
common)
nSource programmable counters
Features
nBuffered inputs and outputs
nTypical Propagation Time
LS157 9 ns
LS158 7 ns
nTypical Power Dissipation
LS157 49 mW
LS158 24 mW
Connection Diagrams
Function Table
Inputs Output Y
Strobe Select A B LS157 LS158
HXXXLH
LLLXLH
LLHXHL
LHXLLH
LHXHHL
H
=
High Level, L =Low Level, X =Don’t Care
Dual-In-Line Package
DS006396-1
Order Number 54LS157DMQB, 54LS157FMQB,
54LS157LMQB, DM54LS157J, DM54LS157W,
DM74LS157M or DM74LS157N
See Package Number E20A, J16A,
M16A, N16E or W16A
Dual-In-Line Package
DS006396-2
Order Number 54LS158DMQB, 54LS158FMQB,
54LS158LMQB, DM54LS158J, DM54LS158W,
DM74LS158M or DM74LS158N
See Package Number E20A, J16A,
M16A, N16E or W16A
March 1998
DM74LS157/DM74LS158 Quad 2-Line to 1-Line Data Selectors/Multiplexers
© 1998 Fairchild Semiconductor Corporation DS006396 www.fairchildsemi.com
Absolute Maximum Ratings (Note 1)
Supply Voltage 7V
Input Voltage 7V
Operating Free Air Temperature Range
DM54LS and 54LS −55˚C to +125˚C
DM74LS 0˚C to +70˚C
Storage Temperature Range −65˚C to +150˚C
Recommended Operating Conditions
Symbol Parameter DM54LS157 DM74LS157 Units
Min Nom Max Min Nom Max
V
CC
Supply Voltage 4.5 5 5.5 4.75 5 5.25 V
V
IH
High Level Input Voltage 2 2 V
V
IL
Low Level Input Voltage 0.7 0.8 V
I
OH
High Level Output Current −0.4 −0.4 mA
I
OL
Low Level Output Current 4 8 mA
T
A
Free Air Operating Temperature −55 125 0 70 ˚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” table are not guaranteed at the absolute maximum ratings. The “Recommended Operating
Conditions” table will define the conditions for actual device operation.
’LS157 Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted)
Symbol Parameter Conditions Min Typ Max Units
(Note 2)
V
I
Input Clamp Voltage V
CC
=Min, I
I
=−18 mA −1.5 V
V
OH
High Level Output V
CC
=Min, I
OH
=Max DM54 2.5 3.4 V
Voltage V
IL
=Max, V
IH
=Min DM74 2.7 3.4
V
OL
Low Level Output V
CC
=Min, I
OL
=Max DM54 0.25 0.4
Voltage V
IL
=Max, V
IH
=Min DM74 0.35 0.5 V
I
OL
=4 mA, V
CC
=Min DM74 0.25 0.4
I
I
Input Current @Max V
CC
=Max S or G 0.2 mA
Input Voltage V
I
=7V A or B 0.1
I
IH
High Level Input V
CC
=Max S or G 40 µA
Current V
I
=2.7V A or B 20
I
IL
Low Level Input V
CC
=Max S or G −0.8 mA
Current V
I
=0.4V A or B −0.4
I
OS
Short Circuit V
CC
=Max DM54 −20 −100 mA
Output Current (Note 3) DM74 −20 −100
I
CC
Supply Current V
CC
=Max (Note 4) 9.7 16 mA
Note 2: All typicals are at VCC =5V, TA=25˚C.
Note 3: Not more than one output should be shorted at a time, and the duration should not exceed one second.
Note 4: ICC is measured with 4.5V applied to all inputs and all outputs open.
’LS157 Switching Characteristics
at V
CC
=5V and T
A
=25˚C
From (Input) R
L
=2kΩ
Symbol Parameter To (Output) C
L
=15 pF C
L
=50 pF Units
Min Max Min Max
t
PLH
Propagation Delay Time Data 14 18 ns
Low to High Level Output to Y
t
PHL
Propagation Delay Time Data 14 23 ns
High to Low Level Output to Y
www.fairchildsemi.com 2
’LS157 Switching Characteristics (Continued)
at V
CC
=5V and T
A
=25˚C
From (Input) R
L
=2kΩ
Symbol Parameter To (Output) C
L
=15 pF C
L
=50 pF Units
Min Max Min Max
t
PLH
Propagation Delay Time Strobe 20 24 ns
Low to High Level Output to Y
t
PHL
Propagation Delay Time Strobe 21 30 ns
High to Low Level Output to Y
t
PLH
Propagation Delay Time Select 23 28 ns
Low to High Level Output to Y
t
PHL
Propagation Delay Time Select 27 32 ns
High to Low Level Output to Y
Recommended Operating Conditions
Symbol Parameter DM54LS158 DM74LS158 Units
Min Nom Max Min Nom Max
V
CC
Supply Voltage 4.5 5 5.5 4.75 5 5.25 V
V
IH
High Level Input Voltage 2 2 V
V
IL
Low Level Input Voltage 0.7 0.8 V
I
OH
High Level Output Current −0.4 −0.4 mA
I
OL
Low Level Output Current 4 8 mA
T
A
Free Air Operating Temperature −55 125 0 70 ˚C
’LS158 Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted)
Symbol Parameter Conditions Min Typ Max Units
(Note 5)
V
I
Input Clamp Voltage V
CC
=Min, I
I
=−18 mA −1.5 V
V
OH
High Level Output V
CC
=Min, I
OH
=Max DM54 2.5 3.4 V
Voltage V
IL
=Max, V
IH
=Min DM74 2.7 3.4
V
OL
Low Level Output V
CC
=Min, I
OL
=Max DM54 0.25 0.4
Voltage V
IL
=Max, V
IH
=Min DM74 0.35 0.5 V
I
OL
=4 mA, V
CC
=Min DM74 0.25 0.4
I
I
Input Current @Max V
CC
=Max S or G 0.2 mA
Input Voltage V
I
=7V A or B 0.1
I
IH
High Level Input V
CC
=Max S or G 40 µA
Current V
I
=2.7V A or B 20
I
IL
Low Level Input V
CC
=Max S or G −0.8 mA
Current V
I
=0.4V A or B −0.4
I
OS
Short Circuit V
CC
=Max DM54 −20 −100 mA
Output Current (Note 6) DM74 −20 −100
I
CC
Supply Current V
CC
=Max (Note 7) 4.8 8 mA
Note 5: All typicals are at VCC =5V, TA=25˚C.
Note 6: Not more than one output should be shorted at a time, and the duration should not exceed one second.
Note 7: ICC is measured with 4.5V applied to all inputs and all outputs open.
3 www.fairchildsemi.com
’LS158 Switching Characteristics
at V
CC
=5V and T
A
=25˚C
From (Input) R
L
=2kΩ
Symbol Parameter To (Output) C
L
=15 pF C
L
=50 pF Units
Min Max Min Max
t
PLH
Propagation Delay Time Data 12 18 ns
Low to High Level Output to Y
t
PHL
Propagation Delay Time Data 12 21 ns
High to Low Level Output to Y
t
PLH
Propagation Delay Time Strobe 17 23 ns
Low to High Level Output to Y
t
PHL
Propagation Delay Time Strobe 18 28 ns
High to Low Level Output to Y
t
PLH
Propagation Delay Time Select 20 24 ns
Low to High Level Output to Y
t
PHL
Propagation Delay Time Select 24 36 ns
High to Low Level Output to Y
Logic Diagrams
LS157
DS006396-3
LS158
DS006396-4
www.fairchildsemi.com 4
5
Physical Dimensions inches (millimeters) unless otherwise noted
Ceramic Leadless Chip Carrier Package (E)
Order Number 54LS157LMQB or 54LS158LMQB
Package Number E20A
16-Lead Ceramic Dual-In-Line Package (J)
Order Number 54LS157DMQB, 54LS158DMQB, DM54LS157J or DM54LS158J
Package Number J16A
www.fairchildsemi.com 6
Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
16-Lead Small Outline Molded Package (M)
Order Number DM74LS157M or DM74LS158M
Package Number M16A
16-Lead Molded Dual-In-Line Package (N)
Order Number DM74LS157N or DM74LS158N
Package Number N16E
7 www.fairchildsemi.com
Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
LIFE SUPPORT POLICY
FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DE-
VICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMI-
CONDUCTOR CORPORATION. As used herein:
1. Life support devices or systems are devices or sys-
tems 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.
2. A critical component in any component of a life support
device or system whose failure to perform can be rea-
sonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
Fairchild Semiconductor
Corporation
Americas
Customer Response Center
Tel: 1-888-522-5372
www.fairchildsemi.com
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Europe Fax: +49 (0) 1 80-530 85 86
Email: europe.support@nsc.com
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Tel: +852 2737-7200
Fax: +852 2314-0061
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Japan Ltd.
Tel: 81-3-5620-6175
Fax: 81-3-5620-6179
16-Lead Ceramic Flat Package (W)
Order Number 54LS157FMQB, 54LS158FMQB, DM54LS157W or DM54LS158W
Package Number W16A
DM74LS157/DM74LS158 Quad 2-Line to 1-Line Data Selectors/Multiplexers
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.
