TECHNICAL DATA
79
Dual D Flip-Flop with Set and Reset
High-Performance Silicon-Gate CMOS
The IN74HC74A is identical in pinout to the LS/ALS74. The
device inputs are compatible with standard CMOS outputs; with pullup
resistors, they are compatible with LS/ALSTTL outputs.
This device consists of two D flip-flops with individual Set, Reset,
and Clock inputs. Information at a D-input is transferred to the
corresponding Q output on the next positive going edge of the clock
input. Both Q and Q outputs are available from each flip-flop. The Set
and Reset inputs are asynchronous.
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
IN74HC74A
ORDERING INFORMATION
IN74HC74AN Plastic
IN74HC74AD SOIC
T
A
= -55
to 125
C for all packages
LOGIC DIAGRAM
PIN 14 =V
CC
PIN 7 = GND
PIN ASSIGNMENT
FUNCTION TABLE
Inputs
Outputs
Set
Reset
Clock
Data
Q
Q
L
H
X
X
H
L
H
L
X
X
L
H
L
L
X
X
H
*
H
*
H
H
H
H
L
H
H
L
L
H
H
H
L
X
No Change
H
H
H
X
No Change
H
H
X
No Change
*Both outputs will remain high as long as Set
and Reset are low, but the output states are
unpredictable if Set and Reset go high
simultaneously.
X = don't care
IN74HC74A
80
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
25
mA
I
CC
DC Supply Current, V
CC
and GND Pins
50
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.
IN74HC74A
81
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
=0.1 V or 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 or V
CC
-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
or V
IL
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
or V
IL
I
OUT
4.0 mA
I
OUT
5.2 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
IH
or 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
IH
or V
IL
I
OUT
4.0 mA
I
OUT
5.2 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
CC
Maximum Quiescent
Supply Current
(per Package)
V
IN
=V
CC
or GND
I
OUT
=0
A
6.0
2.0
20
80
A
IN74HC74A
82
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
f
max
Maximum Clock Frequency (50% Duty Cycle)
(Figures 1 and 4)
2.0
4.5
6.0
6.0
30
35
4.8
24
28
4.0
20
24
MHz
t
PLH
, t
PHL
Maximum Propagation Delay, Clock to Q or Q
(Figures 1 and 4)
2.0
4.5
6.0
100
20
17
125
25
21
150
30
26
ns
t
PLH
, t
PHL
Maximum Propagation Delay, Set or Reset to Q
or Q (Figures 2 and 4)
2.0
4.5
6.0
105
21
18
130
26
22
160
32
27
ns
t
TLH
, t
THL
Maximum Output Transition Time, Any Output
(Figures 1 and 4)
2.0
4.5
6.0
75
15
13
95
19
16
110
22
19
ns
C
IN
Maximum Input Capacitance
-
10
10
10
pF
Power Dissipation Capacitance (Per Flip-Flop)
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
39
pF
TIMING REQUIREMENTS
(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
su
Minimum Setup Time, Data to Clock
(Figure 3)
2.0
4.5
6.0
80
16
14
100
20
17
120
24
20
ns
t
h
Minimum Hold Time, Clock to Data
(Figure 3)
2.0
4.5
6.0
3.0
3.0
3.0
3.0
3.0
3.0
3.0
3.0
3.0
ns
t
rec
Minimum Recovery Time, Set or
Reset Inactive to Clock (Figure 2)
2.0
4.5
6.0
8.0
8.0
8.0
8.0
8.0
8.0
8.0
8.0
8.0
ns
t
w
Minimum Pulse Width, Clock (Figure
1)
2.0
4.5
6.0
60
12
10
75
15
13
90
18
15
ns
t
w
Minimum Pulse Width, Set or Reset
(Figure 2)
2.0
4.5
6.0
60
12
10
75
15
13
90
18
15
ns
t
r
, t
f
Maximum Input Rise and Fall Times
(Figure 1)
2.0
4.5
6.0
1000
500
400
1000
500
400
1000
500
400
ns
IN74HC74A
83
Figure 1. Switching Waveform
Figure 2. Switching Waveform
Figure 3. Switching Waveform
Figure 4.Test Circuit
EXPANDED LOGIC DIAGRAM
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