MC74AC157
MC74ACT157
Quad 2 Input Multiplexer
The MC74AC157/74ACT157 is a high-speed quad 2-input multiplexer. Four
bits of data from two sources can be selected using the common Select and Enable
inputs. The four outputs present the selected data in the true (noninverted) form.
The MC74AC157/74ACT157 can also be used as a function generator.
•
Outputs Source/Sink 24 mA
• ′ACT157
Has TTL Compatible Inputs
QUAD 2-INPUT
MULTIPLEXER
VCC
16
E
15
I0c
14
I1c
13
Zc
12
I0d
11
I1d
10
Zd
9
N SUFFIX
CASE 648-08
PLASTIC
PIN NAMES
I0a–I0d
I1a–I1d
E
S
Za–Zd
Source 0 Data Inputs
Source 1 Data Inputs
Enable Input
Select Input
Outputs
1
S
2
I0a
3
I1a
4
Za
5
I0b
6
I1b
7
Zb
8
GND
D SUFFIX
CASE 751B-05
PLASTIC
TRUTH TABLE
Inputs
E
H
L
L
L
L
S
X
H
H
L
L
I0
X
X
X
L
H
I1
X
L
H
X
X
Outputs
Z
L
L
H
L
H
LOGIC SYMBOL
E I0a I1a I0b I1b I0c I1c I0d I1d
S
Za
Zb
Zc
Zd
H = HIGH Voltage Level
L = LOW Voltage Level
X = Immaterial
FACT DATA
5-1
MC74AC157 MC74ACT157
FUNCTIONAL DESCRIPTION
The MC74AC157/74ACT157 is a quad 2-input multiplexer.
It selects four bits of data from two sources under the control
of a common Select input (S). The Enable input (E) is
active-LOW. When E is HIGH, all of the outputs (Z) are forced
LOW regardless of all other inputs. The MC74AC157/
74ACT157 is the logic implementation of a 4-pole, 2-position
switch where the position of the switch is determined by the
logic levels supplied to the Select input. The logic equations for
the outputs are shown below:
Za = E
•
(I1a
•
S+I0a
•
S)
Zb = E
•
(I1b
•
S+I0b
•
S)
Zc = E
•
(I1c
•
S+I0c
•
S)
Zd = E
•
(I1d
•
S+I0d
•
S)
A common use of the MC74AC157/74ACT157 is the
moving of data from two groups of registers to four common
output busses. The particular register from which the data
comes is determined by the state of the Select input. A less
obvious use is as a function generator. The MC74AC157/
74ACT157 can generate any four of the sixteen different
functions of two variables with one variable common. This is
useful for implementing gating functions.
LOGIC DIAGRAM
I0a
I1a
I0b
I1b
I0c
I1c
I0d
I1d
E
S
Za
Zb
Zc
Zd
Please note that this diagram is provided only for the understanding of logic
operations and should not be used to estimate propagation delays.
MAXIMUM RATINGS*
Symbol
VCC
Vin
Vout
Iin
Iout
ICC
Tstg
Parameter
DC Supply Voltage (Referenced to GND)
DC Input Voltage (Referenced to GND)
DC Output Voltage (Referenced to GND)
DC Input Current, per Pin
DC Output Sink/Source Current, per Pin
DC VCC or GND Current per Output Pin
Storage Temperature
Value
–0.5 to +7.0
–0.5 to VCC +0.5
–0.5 to VCC +0.5
±20
±50
±50
–65 to +150
Unit
V
V
V
mA
mA
mA
°C
* Maximum Ratings are those values beyond which damage to the device may occur. Functional operation should be restricted to the Recommended
Operating Conditions.
FACT DATA
5-2
MC74AC157 MC74ACT157
RECOMMENDED OPERATING CONDITIONS
Symbol
VCC
Vin, Vout
Supply Voltage
DC Input Voltage, Output Voltage (Ref. to GND)
VCC @ 3.0 V
tr, tf
Input Rise and Fall Time (Note 1)
′AC
Devices except Schmitt Inputs
VCC @ 4.5 V
VCC @ 5.5 V
tr, tf
TJ
TA
IOH
IOL
Input Rise and Fall Time (Note 2)
′ACT
Devices except Schmitt Inputs
Junction Temperature (PDIP)
Operating Ambient Temperature Range
Output Current — High
Output Current — Low
–40
25
VCC @ 4.5 V
VCC @ 5.5 V
Parameter
′AC
′ACT
Min
2.0
4.5
0
150
40
25
10
ns/V
8.0
140
85
–24
24
°C
°C
mA
mA
ns/V
Typ
5.0
5.0
Max
6.0
5.5
VCC
V
Unit
V
1. Vin from 30% to 70% VCC; see individual Data Sheets for devices that differ from the typical input rise and fall times.
2. Vin from 0.8 V to 2.0 V; see individual Data Sheets for devices that differ from the typical input rise and fall times.
DC CHARACTERISTICS
74AC
Symbol
Parameter
VCC
(V)
TA = +25°C
Typ
VIH
Minimum High Level
Input Voltage
3.0
4.5
5.5
3.0
4.5
5.5
3.0
4.5
5.5
3.0
4.5
5.5
VOL
Maximum Low Level
Output Voltage
3.0
4.5
5.5
3.0
4.5
5.5
IIN
IOLD
IOHD
ICC
Maximum Input
Leakage Current
†Minimum Dynamic
Output Current
Maximum Quiescent
Supply Current
5.5
5.5
5.5
5.5
8.0
0.002
0.001
0.001
1.5
2.25
2.75
1.5
2.25
2.75
2.99
4.49
5.49
74AC
TA =
–40°C to +85°C
Unit
Conditions
Guaranteed Limits
2.1
3.15
3.85
0.9
1.35
1.65
2.9
4.4
5.4
2.56
3.86
4.86
0.1
0.1
0.1
0.36
0.36
0.36
±0.1
2.1
3.15
3.85
0.9
1.35
1.65
2.9
4.4
5.4
2.46
3.76
4.76
0.1
0.1
0.1
0.44
0.44
0.44
±1.0
75
–75
80
V
VOUT = 0.1 V
or VCC – 0.1 V
VOUT = 0.1 V
or VCC – 0.1 V
IOUT = –50
µA
V
*VIN = VIL or VIH
–12 mA
IOH
–24 mA
–24 mA
IOUT = 50
µA
V
*VIN = VIL or VIH
12 mA
IOL
24 mA
24 mA
VI = VCC, GND
VOLD = 1.65 V Max
VOHD = 3.85 V Min
VIN = VCC or GND
VIL
Maximum Low Level
Input Voltage
V
VOH
Minimum High Level
Output Voltage
V
V
µA
mA
mA
µA
* All outputs loaded; thresholds on input associated with output under test.
† Maximum test duration 2.0 ms, one output loaded at a time.
Note: IIN and ICC @ 3.0 V are guaranteed to be less than or equal to the respective limit @ 5.5 V VCC.
FACT DATA
5-3
MC74AC157 MC74ACT157
AC CHARACTERISTICS
(For Figures and Waveforms — See Section 3)
74AC
Symbol
Parameter
VCC*
(V)
Min
tPLH
tPHL
tPLH
tPHL
tPLH
tPHL
Propagation Delay
S to Zn
Propagation Delay
S to Zn
Propagation Delay
E to Zn
Propagation Delay
En to Zn
Propagation Delay
In to Zn
Propagation Delay
In to Zn
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
TA = +25°C
CL = 50 pF
Typ
7.0
5.5
6.5
5.0
7.0
5.5
6.5
5.5
5.0
4.0
5.0
4.0
Max
11.5
9.0
11.0
8.5
11.5
9.0
11.0
9.0
8.5
6.5
8.0
6.5
74AC
TA = –40°C
to +85°C
CL = 50 pF
Min
1.5
1.5
1.5
1.0
1.5
1.5
1.5
1.0
1.0
1.0
1.0
1.0
Max
13.0
10.0
12.0
9.5
13.0
10.0
12
9.5
9.0
7.0
9.0
7.0
ns
ns
ns
ns
ns
ns
3-6
3-6
3-6
3-6
3-5
3-5
Unit
Fig.
No.
* Voltage Range 3.3 V is 3.3 V
±0.3
V.
Voltage Range 5.0 V is 5.0 V
±0.5
V.
DC CHARACTERISTICS
74ACT
Symbol
Parameter
VCC
(V)
TA = +25°C
Typ
VIH
VIL
VOH
Minimum High Level
Input Voltage
Maximum Low Level
Input Voltage
Minimum High Level
Output Voltage
4.5
5.5
4.5
5.5
4.5
5.5
4.5
5.5
VOL
Maximum Low Level
Output Voltage
4.5
5.5
4.5
5.5
IIN
∆I
CCT
IOLD
IOHD
ICC
Maximum Input
Leakage Current
Additional Max. ICC/Input
†Minimum Dynamic
Output Current
Maximum Quiescent
Supply Current
5.5
5.5
5.5
5.5
5.5
8.0
0.6
0.001
0.001
1.5
1.5
1.5
1.5
4.49
5.49
74ACT
TA =
–40°C to +85°C
Unit
Conditions
Guaranteed Limits
2.0
2.0
0.8
0.8
4.4
5.4
3.86
4.86
0.1
0.1
0.36
0.36
±0.1
2.0
2.0
0.8
0.8
4.4
5.4
3.76
4.76
0.1
0.1
0.44
0.44
±1.0
1.5
75
–75
80
V
V
V
VOUT = 0.1 V
or VCC – 0.1 V
VOUT = 0.1 V
or VCC – 0.1 V
IOUT = –50
µA
*VIN = VIL or VIH
–24 mA
IOH
–24 mA
IOUT = 50
µA
*VIN = VIL or VIH
24 mA
IOL
24 mA
VI = VCC, GND
VI = VCC – 2.1 V
VOLD = 1.65 V Max
VOHD = 3.85 V Min
VIN = VCC or GND
V
V
V
µA
mA
mA
mA
µA
* All outputs loaded; thresholds on input associated with output under test.
† Maximum test duration 2.0 ms, one output loaded at a time.
FACT DATA
5-4
MC74AC157 MC74ACT157
AC CHARACTERISTICS
(For Figures and Waveforms — See Section 3)
74ACT
Symbol
Parameter
VCC*
(V)
Min
tPLH
tPHL
tPLH
tPHL
tPLH
tPHL
Propagation Delay
S to Zn
Propagation Delay
S to Zn
Propagation Delay
En to Zn
Propagation Delay
En to Zn
Propagation Delay
In to Zn
Propagation Delay
In to Zn
5.0
5.0
5.0
5.0
5.0
5.0
2.0
2.0
1.5
1.5
1.5
1.5
TA = +25°C
CL = 50 pF
Typ
Max
9.0
9.5
10
8.5
7.0
7.5
74ACT
TA = –40°C
to +85°C
CL = 50 pF
Min
1.5
2.0
1.5
1.0
1.0
1.0
Max
10.0
10.5
11.5
9.0
8.5
8.5
ns
ns
ns
ns
ns
ns
3-6
3-6
3-6
3-6
3-5
3-5
Unit
Fig.
No.
* Voltage Range 5.0 V is 5.0 V
±0.5
V.
CAPACITANCE
Symbol
CIN
CPD
Input Capacitance
Power Dissipation Capacitance
Parameter
Value
Typ
4.5
50
Unit
pF
pF
Test Conditions
VCC = 5.0 V
VCC = 5.0 V
FACT DATA
5-5
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