HD74LS74A
Function Table
Input
Preset
L
H
L
H
H
Clear
H
L
L
H
H
Clock
X
X
X
↑
↑
D
X
X
X
H
L
Q
H
L
H*
H
L
Output
Q
L
H
H*
L
H
H
H
L
X
Q
0
Q
0
H; high level, L; low level, X; irrelevant,
↑;
transition from low to high level,
Q
0
; level of Q before the indicated steady-state input conditions were established.
Q
0
; complement of
Q
0
or level of Q before the indicated steady-state input conditions were established.
*;This configuration is nonstable, that is, it will not persist when preset and clear inputs return to their inactive (high) level.
Absolute Maximum Ratings
Item
Supply voltage
Input voltage
Power dissipation
Storage temperature
Symbol
V
CC
V
IN
P
T
Tstg
Ratings
7
7
400
–65 to +150
Unit
V
V
mW
°C
Note: Voltage value, unless otherwise noted, are with respect to network ground terminal.
Recommended Operating Conditions
Item
Supply voltage
Output current
Operating temperature
Clock frequency
Pulse width
Setup time
Hold time
Clock High
Clear Preset
“H” Data
“L” Data
Symbol
V
CC
I
OH
I
OL
Topr
f
clock
t
w
t
w
t
su
t
su
t
h
Min
4.75
—
—
–20
0
25
25
20↑
20↑
5↑
Typ
5.00
—
—
25
—
—
—
—
—
—
Max
5.25
–400
8
75
25
—
—
—
—
—
Unit
V
µA
mA
°C
MHz
ns
ns
ns
Note:
↑;
The arrow indicates the rising edge.
Rev.3.00, Jul.22.2005, page 2 of 7