TECHNICAL DATA
IN74AC157
Quad 2-Input Data Selector/Multiplexer
High-Speed Silicon-Gate CMOS
The IN74AC157 is identical in pinout to the LS/ALS157,
HC/HCT157. The device inputs are compatible with standard CMOS
outputs; with pullup resistors, they are compatible with LS/ALS outputs.
This device routes 2 nibbles (A or B) to a single port (Y) as
determined by the Select input. The data is presented at the outputs in
noninvertered form. A high level on the Output Enable input sets all four
Y outputs to a low level.
•
Outputs Directly Interface to CMOS, NMOS, and TTL
•
Operating Voltage Range: 2.0 to 6.0 V
•
Low Input Current: 1.0
μA;
0.1μA @ 25°C
•
High Noise Immunity Characteristic of CMOS Devices
•
Outputs Source/Sink 24 mA
ORDERING INFORMATION
IN74AC157N Plastic
IN74AC157D SOIC
T
A
= -40° to 85° C for all packages
PIN ASSIGNMENT
LOGIC DIAGRAM
FUNCTION TABLE
Inputs
PIN 16 =V
CC
PIN 8 = GND
Output
Enable
H
L
L
Select
X
L
H
Outputs
Y0-Y3
L
A0-A3
B0-B3
X=don’t care
A0-A3,B0-B3=the levels of the respective
Data-Word Inputs
Rev. 00
IN74AC157
MAXIMUM RATINGS
*
Symbol
V
CC
V
IN
V
OUT
I
IN
I
OUT
I
CC
P
D
Tstg
T
L
*
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 Supply Current, V
CC
and GND Pins
Power Dissipation in Still Air, Plastic DIP+
SOIC Package+
Storage Temperature
Lead Temperature, 1 mm from Case for 10 Seconds
(Plastic DIP or SOIC Package)
Value
-0.5 to +7.0
-0.5 to V
CC
+0.5
-0.5 to V
CC
+0.5
±20
±50
±50
750
500
-65 to +150
260
Unit
V
V
V
mA
mA
mA
mW
°C
°C
Maximum Ratings are those values beyond which damage to the device may occur.
Functional operation should be restricted to the Recommended Operating Conditions.
+Derating - Plastic DIP: - 10 mW/°C from 65° to 125°C
SOIC Package: : - 7 mW/°C from 65° to 125°C
RECOMMENDED OPERATING CONDITIONS
Symbol
V
CC
V
IN
, V
OUT
T
J
T
A
I
OH
I
OL
t
r
, t
f
Parameter
DC Supply Voltage (Referenced to GND)
DC Input Voltage, Output Voltage (Referenced to GND)
Junction Temperature (PDIP)
Operating Temperature, All Package Types
Output Current - High
Output Current - Low
Input Rise and Fall Time
*
(except Schmitt Inputs)
V
CC
=3.0 V
V
CC
=4.5 V
V
CC
=5.5 V
0
0
0
-40
Min
2.0
0
Max
6.0
V
CC
140
+85
-24
24
150
40
25
Unit
V
V
°C
°C
mA
mA
ns/V
*
V
IN
from 30% to 70% V
CC
This device contains protection circuitry to guard against damage due to high static voltages or electric fields.
However, precautions must be taken to avoid applications of any voltage higher than maximum rated voltages to this
high-impedance circuit. For proper operation, V
IN
and V
OUT
should be constrained to the range GND≤(V
IN
or
V
OUT
)≤V
CC
.
Unused inputs must always be tied to an appropriate logic voltage level (e.g., either GND or V
CC
). Unused
outputs must be left open.
Rev. 00
IN74AC157
DC ELECTRICAL CHARACTERISTICS
(Voltages Referenced to GND)
V
CC
Symbol
V
IH
Parameter
Minimum High-
Level Input Voltage
Maximum Low -
Level Input Voltage
Minimum High-
Level Output Voltage
Test Conditions
V
OUT
=0.1 V or V
CC
-0.1 V
V
3.0
4.5
5.5
3.0
4.5
5.5
3.0
4.5
5.5
3.0
4.5
5.5
3.0
4.5
5.5
3.0
4.5
5.5
5.5
5.5
5.5
5.5
8.0
Guaranteed Limits
25
°C
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
-40°C to
85°C
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
μA
mA
mA
μA
V
Unit
V
V
IL
V
OUT
=0.1 V or V
CC
-0.1 V
V
V
OH
I
OUT
≤
-50
μA
V
V
IN
=V
IH
or V
IL
I
OH
=-12 mA
I
OH
=-24 mA
I
OH
=-24 mA
V
OL
Maximum Low-
Level Output Voltage
I
OUT
≤
50
μA
*
V
IN
=V
IH
or V
IL
I
OL
=12 mA
I
OL
=24 mA
I
OL
=24 mA
I
IN
I
OLD
I
OHD
I
CC
Maximum Input
Leakage Current
+Minimum Dynamic
Output Current
+Minimum Dynamic
Output Current
Maximum Quiescent
Supply Current
(per Package)
V
IN
=V
CC
or GND
V
OLD
=1.65 V Max
V
OHD
=3.85 V Min
V
IN
=V
CC
or GND
*
*
All outputs loaded; thresholds on input associated with output under test.
+Maximum test duration 2.0 ms, one output loaded at a time.
Note: I
IN
and I
CC
@ 3.0 V are guaranteed to be less than or equal to the respective limit @ 5.5 V V
CC
Rev. 00
IN74AC157
AC ELECTRICAL CHARACTERISTICS
(C
L
=50pF,Input t
r
=t
f
=3.0 ns)
V
CC*
Symbol
Parameter
V
Guaranteed Limits
25
°C
Min
t
PLH
t
PHL
t
PLH
t
PHL
t
PLH
t
PHL
C
IN
Propagation Delay, Input A or B to Output Y
(Figure 1)
Propagation Delay, Input A or B to Output Y
(Figure 1)
Propagation Delay, Select to Output Y (Figure
2)
Propagation Delay, Select to Output Y (Figure
2)
Propagation Delay, Output Enable to
Output Y (Figure 3)
Propagation Delay, Output Enable to
Output Y (Figure 3)
Maximum Input Capacitance
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
3.3
5.0
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
4.5
Max
8.5
6.5
8.0
6.5
11.5
9.0
11.0
8.5
11.5
9.0
11.0
9.0
-40°C to
85°C
Min
1.0
1.0
1.0
1.0
1.5
1.5
1.5
1.0
1.5
1.5
1.5
1.0
4.5
Max
9.0
7.0
9.0
7.0
13.0
10.0
12.0
9.5
13.0
10.0
12.0
9.5
ns
ns
ns
ns
ns
ns
pF
Unit
Typical @25°C,V
CC
=5.0 V
C
PD
*
Power Dissipation Capacitance
50
pF
Voltage Range 3.3 V is 3.3 V
±0.3
V
Voltage Range 5.0 V is 5.0 V
±0.5
V
Figure 1. Switching Waveforms
Figure 2. Switching Waveforms
Figure 3. Switching Waveforms
Rev. 00
IN74AC157
EXPANDED LOGIC DIAGRAM
A0
B0
A1
B1
A2
B2
A3
B3
OE SELECT
Y0
Y1
Y2
Y3
Rev. 00
PCB设计
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