74F646 • 74F646B • 74F648
AC Electrical Characteristics
74F646/74F648
T
A
= +25°C
Symbol
Parameter
V
CC
= +5.0V
C
L
=
50 pF
Min
f
MAX
t
PLH
t
PHL
t
PLH
t
PHL
t
PLH
t
PHL
t
PLH
t
PHL
t
PZH
t
PZL
t
PHZ
t
PLZ
t
PZH
t
PZL
t
PHZ
t
PLZ
Maximum Clock Frequency
Propagation Delay
Clock to Bus
Propagation Delay
Bus to Bus (74F646)
Propagation Delay
Bus to Bus (74F648)
Propagation Delay
SBA or SAB to A or B
Enable Time
OE to A or B
Disable Time
OE to A or B
Enable Time
DIR to A or B
Disable Time
DIR to A or B
90
2.0
2.0
1.0
1.0
2.0
1.0
2.0
2.0
2.0
2.0
1.0
2.0
2.0
2.0
1.0
2.0
7.0
8.0
7.0
6.5
8.5
7.5
8.5
8.0
8.5
12.0
7.5
9.0
14.0
13.0
9.0
11.0
Max
T
A
= −55°C
to
+125°C
V
CC
= +5.0V
C
L
=
50 pF
Min
75
2.0
2.0
1.0
1.0
1.0
1.0
2.0
2.0
2.0
2.0
1.0
2.0
2.0
2.0
1.0
2.0
8.5
9.5
8.0
8.0
10.0
9.0
11.0
10.0
10.0
13.5
9.0
11.0
16.0
15.0
10.0
12.0
Max
T
A
=
0°C to
+70°C
V
CC
= +5.0V
C
L
=
50 pF
Min
90
2.0
2.0
1.0
1.0
2.0
1.0
2.0
2.0
2.0
2.0
1.0
2.0
2.0
2.0
1.0
2.0
8.0
9.0
7.5
7.0
9.0
8.0
9.5
9.0
9.0
12.5
8.5
9.5
15.0
14.0
9.5
11.5
Max
MHz
ns
ns
ns
ns
ns
Units
ns
ns
ns
AC Operating Requirements
74F646/74F648
T
A
= +25°C
Symbol
Parameter
V
CC
= +5.0V
Min
t
S
(H)
t
S
(L)
t
H
(H)
t
H
(L)
t
W
(H)
t
W
(L)
Setup Time, HIGH or LOW
Bus to Clock
Hold Time, HIGH or LOW
Bus to Clock
Clock Pulse Width
HIGH or LOW
5.0
5.0
2.0
2.0
5.0
5.0
Max
T
A
= −55°C
to
+125°C
V
CC
= +5.0V
Min
5.0
5.0
2.5
2.5
5.0
5.0
Max
T
A
=
0°C to
+70°C
V
CC
= +5.0V
Min
5.0
5.0
2.0
2.0
5.0
5.0
Max
ns
ns
ns
Units
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