TL/F/6404
54LS174/DM54LS174/DM74LS174, 54LS175/DM54LS175/DM74LS175
Hex/Quad D Flip-Flops with Clear
June 1989
54LS174/DM54LS174/DM74LS174,
54LS175/DM54LS175/DM74LS175
Hex/Quad D Flip-Flops with Clear
General Description
These positive-edge-triggered flip-flops utilize TTL circuitry
to implement D-type flip-flop logic. All have a direct clear
input, and the quad (175) versions feature complementary
outputs from each flip-flop.
Information at the D inputs meeting the setup time requirements is transferred to the Q outputs on the positive-going
edge of the clock pulse. Clock triggering occurs at a particular voltage level and is not directly related to the transition
time of the positive-going pulse. When the clock input is at
either the high or low level, the D input signal has no effect
at the output.
Features
Y
LS174 contains six flip-flops with single-rail outputs
Y
LS175 contains four flip-flops with double-rail outputs
Y
Buffered clock and direct clear inputs
Y
Individual data input to each flip-flop
Y
Applications include:
Buffer/storage registers
Shift registers
Pattern generators
Y
Typical clock frequency 40 MHz
Y
Typical power dissipation per flip-flop 14 mW
Y
Alternate Military/Aerospace device (54LS174,
54LS175) is available. Contact a National Semiconductor Sales Office/Distributor for specifications.
Connection Diagrams
Dual-In-Line Package
TL/F/6404– 1
Order Number 54LS174DMQB, 54LS174FMQB,
54LS174LMQB, DM54LS174J,
DM54LS174W, DM74LS174M or DM74LS174N
See NS Package Number E20A, J16A,
M16A, N16E or W16A
Dual-In-Line Package
TL/F/6404– 2
Order Number 54LS175DMQB, 54LS175FMQB,
54LS175LMQB, DM54LS175J
DM54LS175W, DM74LS175M or DM74LS175N
See NS Package Number E20A, J16A,
M16A, N16E or W16A
Function Table (Each Flip-Flop)
Inputs Outputs
Clear Clock D Q Q
²
LXXLH
H
u
HH L
H
u
LL H
HLXQ
0
Q
0
H
e
High Level (steady state)
L
e
Low Level (steady state)
X
e
Don’t Care
u
e
Transition from low to high level
Q
0
e
The level of Q before the indicated steady-state input conditions were
established.
²
e
LS175 only
C
1995 National Semiconductor Corporation RRD-B30M105/Printed in U. S. A.