HD74HC173
4-bit D-type Register (with 3-state Outputs)
Description
The four D type Flip-Flops operate synchronously from a common clock. The 3-state outputs allow the
device to be used in bus organized systems. The outputs are placed in the 3-stage mode when either of the
output disable pins are in the logic high level.
The input disable allows the flip-flops to remain in their present states without having to disrupt the clock.
If either of the 2 input disables are taken to a logic high level, the Q outputs are fed back to the inputs,
forcing the flip-flops to remain in the same state. Clearing is enabled by taking the clear input to a logic
high level. The data outputs change state on the positive going edge of the clock.
Features
•
•
•
•
•
High Speed Operation: t
pd
(Clock to Q) = 14 ns typ (C
L
= 50 pF)
High Output Current: Fanout of 10 LSTTL Loads
Wide Operating Voltage: V
CC
= 2 to 6 V
Low Input Current: 1 µA max
Low Quiescent Supply Current: I
CC
(static) = 4 µA max (Ta = 25°C)
Function Table
Inputs
Data Enable
Clear
H
L
L
L
L
L
Clock
X
L
G
1
X
X
H
X
L
L
G
2
X
X
X
H
L
L
Data D
X
X
X
X
L
H
Output Q
L
Q
0
Q
0
Q
0
L
H
Note: When either M or N (or both) is (are) high the output is disabled to the high-impedance state;
however sequential operation of the flip-flops is not affected.
HD74HC173
Pin Arrangement
Output
Control
M 1
N 2
1Q 3
2Q 4
Output
Control Clear
1Q
2Q
3Q
4Q
1D
2D
3D
4D
16 V
CC
15 Clear
14 1D
13 2D
12 3D
11 4D
10 G
2
9 G
1
Data
Enable
Input
Data
Input
Output
3Q 5
4Q 6
Clock 7
GND 8
CK Data
Enable
(Top view)
Absolute Maximum Ratings
Item
Supply voltage range
Input voltage
Output voltage
DC current drain per pin
DC current drain per VCC, GND
DC input diode current
DC output diode current
Power dissipation per package
Storage temperature
Symbol
V
CC
V
IN
V
OUT
I
OUT
I
CC
, I
GND
I
IK
I
OK
P
T
Tstg
Rating
–0.5 to +7.0
–0.5 to V
CC
+ 0.5
–0.5 to V
CC
+ 0.5
±35
±75
±20
±20
500
–65 to +150
Unit
V
V
V
mA
mA
mA
mA
mW
°C
2
Embedded System
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