TECHNICAL DATA
KK74HC257A
Quad 2-Input Data Selector/Multiplexer
with 3-State Outputs
High-Performance Silicon-Gate CMOS
The KK74HC257A is identical in pinout to the LS/ALS257. The
device inputs are compatible with standard CMOS outputs; with pullup
resistors, they are compatible with LS/ALSTTL outputs.
This device selects a (4-bit) nibble from either the A or B inputs as
determined by the Select input. The nibble is presented at the outputs in
noninverted from when the Output Enable pin is at a low level. A high
level on the Output Enable pin switches the outputs into the high-
impedance state.
•
Outputs Directly Interface to CMOS, NMOS, and TTL
•
Operating Voltage Range: 2.0 to 6.0 V
•
Low Input Current: 1.0
µA
•
High Noise Immunity Characteristic of CMOS Devices
ORDERING INFORMATION
KK74HC257AN Plastic
KK74HC257AD SOIC
T
A
= -55° to 125° C for all packages
PIN ASSIGNMENT
LOGIC DIAGRAM
FUNCTION TABLE
Inputs
Output
Enable
H
L
PIN 16 =V
CC
PIN 8 = GND
L
Select
X
L
H
Outputs
Y0-Y3
Z
A0-A3
B0-B3
X=don’t care
Z = high-impedance state
A0-A3,B0-B3=the levels of the respective
Nibble Inputs
1
KK74HC257A
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 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
-1.5 to V
CC
+1.5
-0.5 to V
CC
+0.5
±20
±35
±75
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
A
t
r
, t
f
Parameter
DC Supply Voltage (Referenced to GND)
DC Input Voltage, Output Voltage (Referenced to GND)
Operating Temperature, All Package Types
Input Rise and Fall Time (Figure 1)
V
CC
=2.0 V
V
CC
=4.5 V
V
CC
=6.0 V
Min
2.0
0
-55
0
0
0
Max
6.0
V
CC
+125
1000
500
400
Unit
V
V
°C
ns
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.
2
KK74HC257A
DC ELECTRICAL CHARACTERISTICS
(Voltages Referenced to GND)
V
CC
Symbol
Parameter
Test Conditions
V
Guaranteed Limit
25
°C
to
-55°C
1.5
3.15
4.2
0.3
0.9
1.2
1.9
4.4
5.9
3.98
5.48
0.1
0.1
0.1
0.26
0.26
±0.1
±0.5
≤85
°C
1.5
3.15
4.2
0.3
0.9
1.2
1.9
4.4
5.9
3.84
5.34
0.1
0.1
0.1
0.33
0.33
±1.0
±5.0
≤125
°C
1.5
3.15
4.2
0.3
0.9
1.2
1.9
4.4
5.9
3.7
5.2
0.1
0.1
0.1
0.4
0.4
±1.0
±10
µA
µA
V
Unit
V
IH
Minimum High-
Level Input Voltage
Maximum Low -
Level Input Voltage
Minimum High-
Level Output Voltage
V
OUT
=0.1 V or V
CC
-0.1 V
⎢I
OUT
⎢≤
20
µA
V
OUT
=0.1 V or V
CC
-0.1 V
⎢I
OUT
⎢ ≤
20
µA
V
IN
=V
IH
or V
IL
⎢I
OUT
⎢ ≤
20
µA
V
IN
=V
IH
or V
IL
⎢I
OUT
⎢ ≤
6.0 mA
⎢I
OUT
⎢ ≤
7.8 mA
2.0
4.5
6.0
2.0
4.5
6.0
2.0
4.5
6.0
4.5
6.0
2.0
4.5
6.0
4.5
6.0
6.0
6.0
V
V
IL
V
V
OH
V
V
OL
Maximum Low-
Level Output Voltage
V
IN
=V
IH
or V
IL
⎢I
OUT
⎢ ≤
20
µA
V
IN
=V
IH
or V
IL
⎢I
OUT
⎢ ≤
6.0 mA
⎢I
OUT
⎢ ≤.7.8
mA
I
IN
I
OZ
Maximum Input
Leakage Current
Maximum Three-
State Leakage
Current
Maximum Quiescent
Supply Current
(per Package)
V
IN
=V
CC
or GND
Output in High-Impedance
State
V
IN
= V
IL
or V
IH
V
OUT
= V
CC
or GND
V
IN
=V
CC
or GND
I
OUT
=0µA
I
CC
6.0
8.0
80
160
µA
3
KK74HC257A
AC ELECTRICAL CHARACTERISTICS
(C
L
=50pF,Input t
r
=t
f
=6.0 ns)
V
CC
Symbol
Parameter
V
Guaranteed Limit
25
°C
to
-55°C
100
20
17
100
20
17
150
30
26
150
30
26
60
12
10
10
15
≤85°C
≤125°C
Unit
t
PLH
, t
PHL
Maximum Propagation Delay, Nibble A or B to
Output Y (Figures 1and 4)
Maximum Propagation Delay , Select to
Output Y (Figures 2 and 4)
Maximum Propagation Delay , Output Enable to
Output Y (Figures 3 and 5)
Maximum Propagation Delay , Output Enable to
Output Y (Figures 3 and 5)
Maximum Output Transition Time, Any Output
(Figures 1 and 4)
Maximum Input Capacitance
Maximum Three-State Output Capacitance
(Output in High-Impedance State)
Power Dissipation Capacitance (Per Package)
2.0
4.5
6.0
2.0
4.5
6.0
2.0
4.5
6.0
2.0
4.5
6.0
2.0
4.5
6.0
-
-
125
25
21
125
25
21
190
38
33
190
38
33
75
15
13
10
15
150
30
26
150
30
26
225
45
38
225
45
38
90
18
15
10
15
ns
t
PLH
, t
PHL
ns
t
PLZ
, t
PHZ
ns
t
PZL
, t
PZH
ns
t
TLH
, t
THL
ns
C
IN
C
OUT
pF
pF
Typical @25°C,V
CC
=5.0 V
39
pF
C
PD
Used to determine the no-load dynamic power
consumption:
P
D
=C
PD
V
CC2
f+I
CC
V
CC
Figure 1. Switching Waveforms
Figure 2. Switching Waveforms
4
KK74HC257A
Figure 3. Switching Waveforms
Figure 4. Test Circuit
Figure 5. Test Circuit
EXPANDED LOGIC DIAGRAM
5
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