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TL/F/6631
DM54L74 Dual Positive-Edge-Triggered D Flip-Flops
with Preset, Clear, and Complementary Outputs
June 1989
DM54L74 Dual Positive-Edge-Triggered D Flip-Flops
with Preset, Clear, and Complementary Outputs
General Description
This device contains two independent positive-edge-triggered D flip-flops with complementary outputs. The information on the D input is accepted by the flip-flops on the positive going edge of the clock pulse. The triggering occurs at a
voltage level and is not directly related to the transition time
of the rising edge of the clock. The data on the D input
may be changed while the clock is low or high without affecting the outputs as long as the data setup and hold times
are not violated. A low logic level on the preset or clear
inputs will set or reset the outputs regardless of the logic
levels of the other inputs.
Connection Diagram
Dual-In-Line Package
TL/F/6631– 1
Order Number DM54L74J or DM54L74W
See NS Package Number J14A or W14B
Function Table
Inputs Outputs
PR CLR CLK D Q Q
LH XXHL
HL XXLH
LL XXH*H*
HH
u
HH L
HH
u
LL H
HH LXQ
O
Q
O
H
e
High Logic Level
X
e
Either Low or High Logic Level
L
e
Low Logic Level
u
e
Positive-going transition.
Q
O
e
The output logic level of Q before the indicated input conditions were
established.
*
e
This configuration is nonstable; that is, it will not persist when either the
preset and/or clear inputs returned to their inactive (high) level.
C
1995 National Semiconductor Corporation RRD-B30M105/Printed in U. S. A.
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Absolute Maximum Ratings (Note)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales
Office/Distributors for availability and specifications.
Supply Voltage 8V
Input Voltage 5.5V
Operating Free Air Temperature Range
DM54L
b
55§Ctoa125§C
Storage Temperature Range
b
65§Ctoa150§C
Note:
The ‘‘Absolute Maximum Ratings’’ are those values
beyond which the safety of the device cannot be guaranteed. The device should not be operated at these limits. The
parametric values defined in the ‘‘Electrical Characteristics’’
table are not guaranteed at the absolute maximum ratings.
The ‘‘Recommended Operating Conditions’’ table will define
the conditions for actual device operation.
Recommended Operating Conditions
Symbol Parameter
DM54L74
Units
Min Nom Max
V
CC
Supply Voltage 4.5 5 5.5 V
V
IH
High Level Input Voltage 2 V
V
IL
Low Level Input Voltage 0.7 V
I
OH
High Level Output Current
b
0.2 mA
I
OL
Low Level Output Current 2 mA
f
CLK
Clock Frequency (Note 2) 0 6 MHz
t
W
Pulse Width (Note 2) Clock High 75
Clock Low 75
ns
Preset Low 75
Clear Low 75
t
SU
Input Setup Time (Notes1&2) 50
u
ns
t
H
Input Hold Time (Notes1&2) 15
u
ns
T
A
Free Air Operating Temperature
b
55 125
§
C
Note 1: The symbol (u) indicates the rising edge of the clock pulse is used for reference.
Note 2: T
A
e
25§C and V
CC
e
5V.
2