Datasheet
SCLS068E − NOVEMBER 1988 − REVISED AUGUST 2003
4
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
timing requirements over recommended operating free-air temperature range (unless otherwise
noted)
V
CC
T
A
= 25°C SN54HCT273 SN74HCT273
UNIT
V
CC
MIN MAX MIN MAX MIN MAX
UNIT
f
clock
Clock frequency
4.5 V 25 16 20
MHz
f
clock
Clock frequency
5.5 V
28 19 23
MHz
CLK high or low
4.5 V 20 30 25
t
w
Pulse duration
CLK high or low
5.5 V 18 25 22
ns
t
w
Pulse duration
CLR low
4.5 V 16 24 20
ns
CLR low
5.5 V 14 20 17
Data
4.5 V 20 30 25
t
su
Setup time before CLK↑
Data
5.5 V 17 25 21
ns
t
su
Setup time before CLK↑
CLR inactive
4.5 V 20 30 25
ns
CLR inactive
5.5 V 17 25 21
t
h
Hold time data after CLK↑
4.5 V 0 0 0
ns
t
h
Hold time data after CLK
↑
5.5 V 0 0 0
ns
switching characteristics over recommended operating free-air temperature range, V
CC
= 5 V ± 0.5 V,
C
L
= 50 pF (unless otherwise noted) (see Figure 1)
FROM
TO
SN54HCT273
PARAMETER
FROM
(INPUT)
TO
(OUTPUT)
V
CC
T
A
= 25°C
MIN
MAX
UNIT
PARAMETER
(INPUT)
(OUTPUT)
V
CC
MIN TYP MAX
MIN
MAX
UNIT
f
max
4.5 V 25 31 16
MHz
f
max
5.5 V 28 37 19
MHz
t
pd
CLR
Any
4.5 V 15 34 50
ns
t
pd
CLR
Any
5.5 V 12 29 42
ns
t
PHL
CLR
Any
4.5 V 17 15 50
ns
t
PHL
CLR
Any
5.5 V 15 34 42
ns
t
t
Any
4.5 V 8 18 22
ns
t
t
Any
5.5 V 7 19 21
ns
switching characteristics over recommended operating free-air temperature range, V
CC
= 5 V ± 0.5 V,
C
L
= 50 pF (unless otherwise noted) (see Figure 1)
FROM
TO
SN74HCT273
PARAMETER
FROM
(INPUT)
TO
(OUTPUT)
V
CC
T
A
= 25°C
MIN
MAX
UNIT
PARAMETER
(INPUT)
(OUTPUT)
V
CC
MIN TYP MAX
MIN
MAX
UNIT
f
max
4.5 V 25 31 20
MHz
f
max
5.5 V 28 37 23
MHz
t
pd
CLR
Any
4.5 V 15 34 42
ns
t
pd
CLR
Any
5.5 V 12 29 36
ns
t
PHL
CLR
Any
4.5 V 17 34 42
ns
t
PHL
CLR
Any
5.5 V 15 29 36
ns
t
t
Any
4.5 V 8 15 19
ns
t
t
Any
5.5 V 7 14 17
ns
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