September 1986
Revised April 2000
DM74LS157 • DM74LS158
Quad 2-Line to 1-Line Data Selectors/Multiplexers
General Description
These data selectors/multiplexers contain inverters and drivers to supply full on-chip data selection to the four output gates. A separate strobe input is provided. A 4-bit word is selected from one of two sources and is routed to the four outputs. The DM74LS157 presents true data whereas the DM74LS158 presents inverted data to minimize propagation delay time.
Applications
•Expand any data input point
•Multiplex dual data buses
•Generate four functions of two variables (one variable is common)
•Source programmable counters
Features
■Buffered inputs and outputs
■Typical Propagation Time DM74LS157 9 ns DM74LS158 7 ns
■Typical Power Dissipation DM74LS157 49 mW DM74LS158 24 mW
Ordering Code:
Order Number |
Package Number |
Package Description |
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DM74LS157M |
M16A |
16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow |
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DM74LS157SJ |
M16D |
16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide |
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DM74LS157N |
N16E |
16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide |
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DM74LS158M |
M16A |
16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow |
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DM74LS158N |
N16E |
16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide |
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Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Connection Diagrams
DM74LS157 DM74LS158
Selectors/Multiplexers Data Line-1 to Line-2 Quad DM74LS158 • DM74LS157
© 2000 Fairchild Semiconductor Corporation |
DS006396 |
www.fairchildsemi.com |
DM74LS157 • DM74LS158
Function Table
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Inputs |
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Output Y |
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Strobe |
Select |
A |
B |
DM74LS157 |
DM74LS158 |
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H |
X |
X |
X |
L |
H |
L |
L |
L |
X |
L |
H |
L |
L |
H |
X |
H |
L |
L |
H |
X |
L |
L |
H |
L |
H |
X |
H |
H |
L |
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H = HIGH Level
L = LOW Level
X = Don’t Care
Logic Diagrams
DM74LS157 |
DM74LS158 |
www.fairchildsemi.com |
2 |
Absolute Maximum Ratings(Note 1)
Supply Voltage |
7V |
Note 1: The “Absolute Maximum Ratings” are those values beyond which |
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the safety of the device cannot be guaranteed. The device should not be |
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Input Voltage |
7V |
operated at these limits. The parametric values defined in the Electrical |
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Characteristics tables are not guaranteed at the absolute maximum ratings. |
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Operating Free Air Temperature Range |
0°C to +70°C |
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The “Recommended Operating Conditions” table will define the conditions |
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Storage Temperature Range |
−65°C to +150°C |
for actual device operation. |
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DM74LS157 Recommended Operating Conditions
Symbol |
Parameter |
Min |
Nom |
Max |
Units |
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VCC |
Supply Voltage |
4.75 |
5 |
5.25 |
V |
VIH |
HIGH Level Input Voltage |
2 |
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V |
VIL |
LOW Level Input Voltage |
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0.8 |
V |
IOH |
HIGH Level Output Current |
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−0.4 |
mA |
IOL |
LOW Level Output Current |
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8 |
mA |
TA |
Free Air Operating Temperature |
0 |
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70 |
°C |
DM74LS157 Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted)
Symbol |
Parameter |
Conditions |
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Min |
Typ |
Max |
Units |
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(Note 2) |
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VI |
Input Clamp Voltage |
VCC = Min, II = −18 mA |
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−1.5 |
V |
VOH |
HIGH Level Output Voltage |
VCC = Min, IOH = Max, VIL = Max, VIH = Min |
2.7 |
3.4 |
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V |
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VOL |
LOW Level |
VCC = Min, IOL = Max, VIL = Max, VIH = Min |
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0.35 |
0.5 |
V |
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Output Voltage |
IOL = 4 mA, VCC = Min |
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0.25 |
0.4 |
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II |
Input Current @ Max |
VCC = Max |
S or G |
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0.2 |
mA |
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Input Voltage |
VI = 7V |
A or B |
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0.1 |
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IIH |
HIGH Level |
VCC = Max |
S or G |
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40 |
μA |
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Input Current |
VI = 2.7V |
A or B |
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20 |
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IIL |
LOW Level |
VCC = Max |
S or G |
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−0.8 |
mA |
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Input Current |
VI = 0.4V |
A or B |
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−0.4 |
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IOS |
Short Circuit Output Current |
VCC = Max (Note 3) |
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−20 |
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−100 |
mA |
ICC |
Supply Current |
VCC = Max (Note 4) |
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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.
DM74LS157 Switching Characteristics
at VCC = 5V and TA = 25°C |
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From (Input) |
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RL = 2 kΩ |
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Symbol |
Parameter |
To (Output) |
CL = 15 pF |
CL = 50 pF |
Units |
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Min |
Max |
Min |
Max |
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tPLH |
Propagation Delay Time |
Data to Y |
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14 |
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18 |
ns |
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LOW-to-HIGH Level Output |
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tPHL |
Propagation Delay Time |
Data to Y |
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14 |
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23 |
ns |
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HIGH-to-LOW Level Output |
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tPLH |
Propagation Delay Time |
Strobe to Y |
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20 |
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24 |
ns |
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LOW-to-HIGH Level Output |
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tPHL |
Propagation Delay Time |
Strobe to Y |
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21 |
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30 |
ns |
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HIGH-to-LOW Level Output |
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tPLH |
Propagation Delay Time |
Select to Y |
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23 |
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28 |
ns |
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LOW-to-HIGH Level Output |
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tPHL |
Propagation Delay Time |
Select to Y |
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27 |
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32 |
ns |
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HIGH-to-LOW Level Output |
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DM74LS158 • DM74LS157
3 |
www.fairchildsemi.com |
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