TECHNICAL DATA
291
Octal 3-State Noninverting
Buffer/Line Driver/Line Receiver
High-Performance Silicon-Gate CMOS
The IN74HC244A is identical in pinout to the LS/ALS244. The
device inputs are compatible with standard CMOS outputs; with pullup
resistors, they are compatible with LS/ALSTTL outputs.
This octal noninverting buffer/line driver/line receiver is designed
to be used with 3-state memory address drivers, clock drivers, and
other bus-oriented systems. The device has noninverting outputs and
two active-low output enables.
Outputs Directly Interface to CMOS, NMOS, and TTL
Operating Voltage Range: 2.0 to 6.0 V
Low Input Current: 1.0
A
High Noise Immunity Characteristic of CMOS Devices
IN74HC244A
ORDERING INFORMATION
IN74HC244AN Plastic
IN74HC244ADW SOIC
T
A
= -55
to 125
C for all packages
FUNCTION TABLE
Inputs
Outputs
Enable A,
Enable B
A,B
YA,YB
L
L
L
L
H
H
H
X
Z
X=don't care
Z = high impedance
LOGIC DIAGRAM
PIN 20=V
CC
PIN 10 = GND
PIN ASSIGNMENT
IN74HC244A
292
MAXIMUM RATINGS
*
Symbol
Parameter
Value
Unit
V
CC
DC Supply Voltage (Referenced to GND)
-0.5 to +7.0
V
V
IN
DC Input Voltage (Referenced to GND)
-1.5 to V
CC
+1.5
V
V
OUT
DC Output Voltage (Referenced to GND)
-0.5 to V
CC
+0.5
V
I
IN
DC Input Current, per Pin
20
mA
I
OUT
DC Output Current, per Pin
35
mA
I
CC
DC Supply Current, V
CC
and GND Pins
75
mA
P
D
Power Dissipation in Still Air, Plastic DIP+
SOIC Package+
750
500
mW
Tstg
Storage Temperature
-65 to +150
C
T
L
Lead Temperature, 1 mm from Case for 10 Seconds
(Plastic DIP or SOIC Package)
260
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
Parameter
Min
Max
Unit
V
CC
DC Supply Voltage (Referenced to GND)
2.0
6.0
V
V
IN
, V
OUT
DC Input Voltage, Output Voltage (Referenced to GND)
0
V
CC
V
T
A
Operating Temperature, All Package Types
-55
+125
C
t
r
, t
f
Input Rise and Fall Time (Figure 1)
V
CC
=2.0 V
V
CC
=4.5 V
V
CC
=6.0 V
0
0
0
1000
500
400
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.
IN74HC244A
293
DC ELECTRICAL CHARACTERISTICS
(Voltages Referenced to GND)
V
CC
Guaranteed Limit
Symbol
Parameter
Test Conditions
V
25
C
to
-55
C
85
C
125
C
Unit
V
IH
Minimum High-Level
Input Voltage
V
OUT
= V
CC
-0.1 V
I
OUT
20
A
2.0
4.5
6.0
1.5
3.15
4.2
1.5
3.15
4.2
1.5
3.15
4.2
V
V
IL
Maximum Low -
Level Input Voltage
V
OUT
=0.1 V
I
OUT
20
A
2.0
4.5
6.0
0.5
1.35
1.8
0.5
1.35
1.8
0.5
1.35
1.8
V
V
OH
Minimum High-Level
Output Voltage
V
IN
=V
IH
I
OUT
20
A
2.0
4.5
6.0
1.9
4.4
5.9
1.9
4.4
5.9
1.9
4.4
5.9
V
V
IN
=V
IH
I
OUT
6.0 mA
I
OUT
7.8 mA
4.5
6.0
3.98
5.48
3.84
5.34
3.7
5.2
V
OL
Maximum Low-Level
Output Voltage
V
IN
= V
IL
I
OUT
20
A
2.0
4.5
6.0
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
V
V
IN
= V
IL
I
OUT
6.0 mA
I
OUT
7.8 mA
4.5
6.0
0.26
0.26
0.33
0.33
0.4
0.4
I
IN
Maximum Input
Leakage Current
V
IN
=V
CC
or GND
6.0
0.1
1.0
1.0
A
I
OZ
Maximum Three-
State Leakage
Current
Output in High-Impedance
State
V
IN
= V
IL
or V
IH
V
OUT
=V
CC
or GND
6.0
0.5
5.0
10.0
A
I
CC
Maximum Quiescent
Supply Current
(per Package)
V
IN
=V
CC
or GND
I
OUT
=0
A
6.0
4.0
40
160
A
IN74HC244A
294
AC ELECTRICAL CHARACTERISTICS
(C
L
=50pF,Input t
r
=t
f
=6.0 ns)
V
CC
Guaranteed Limit
Symbol
Parameter
V
25
C
to
-55
C
85
C
125
C
Unit
t
PLH
, t
PHL
Maximum Propagation Delay, A to YA or B to
YB (Figures 1 and 3)
2.0
4.5
6.0
96
18
15
115
23
20
135
27
23
ns
t
PLZ
, t
PHZ
Maximum Propagation Delay , Output Enable to
YA or YB (Figures 2 and 4)
2.0
4.5
6.0
110
22
19
140
28
24
165
33
28
ns
t
PZL
, t
PZH
Maximum Propagation Delay , Output Enable to
YA or YB (Figures 2 and 4)
2.0
4.5
6.0
110
22
19
140
28
24
165
33
28
ns
t
TLH
, t
THL
Maximum Output Transition Time, Any Output
(Figures 1 and 3)
2.0
4.5
6.0
60
12
10
75
15
13
90
18
15
ns
C
IN
Maximum Input Capacitance
-
10
10
10
pF
C
OUT
Maximum Three-State Output Capacitance
(Output in High-Impedance State)
-
15
15
15
pF
Power Dissipation Capacitance (Per Buffer)
Typical @25
C,V
CC
=5.0 V
C
PD
Used to determine the no-load dynamic power
consumption:
P
D
=C
PD
V
CC
2
f+I
CC
V
CC
34
pF
Figure 1. Switching Waveforms
Figure 2. Switching Waveforms
Figure 3. Test Circuit
Figure 4. Test Circuit
IN74HC244A
295
EXPANDED LOGIC DIAGRAM
(1/8 of the Device)
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