MC74AC574, MC74ACT574
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2
FUNCTIONAL DESCRIPTION
The MC74AC574/74ACT574 consists of eight edge-
triggered flip−flops with individual D−type inputs and
3−state true outputs. The buffered clock and buffered Output
Enable are common to all flip−flops. The eight flip−flops
will store the state of their individual D inputs that meet the
setup and hold time requirements on the LOW−to−HIGH
Clock (CP) transition. With the Output Enable (OE) LOW,
the contents of the eight flip−flops are available at the
outputs. When OE is HIGH, the outputs go to the high
impedance state. Operation of the OE input does not affect
the state of the flip−flops.
FUNCTION TABLE
Inputs Internal Outputs
Function
OE CP D Q O
n
H H L NC Z Hold
H HH NC Z Hold
H LL Z Load
H HH Z Load
L LL L Data Available
L HH H Data Available
L HL NC NC No Change in Data
L H H NC NC No Change in Data
H = HIGH Voltage Level
L = LOW Voltage Level
X = Immaterial
Z = High Impedance
= LOW-to-HIGH Clock Transition
NC = No Change
Figure 3. Logic Diagram
D
0
D
1
D
2
D
3
D
4
D
5
D
6
D
7
CD
Q
O
0
O
1
O
2
O
3
O
4
O
5
O
6
O
7
OE
CP
CD
Q
CD
Q
CD
Q
CD
Q
CD
Q
CD
Q
CD
Q
NOTE: This diagram is provided only for the understanding of logic operations
and should not be used to estimate propagation delays.
MAXIMUM RATINGS
Symbol Parameter Value Unit
V
CC
DC Supply Voltage (Referenced to GND) −0.5 to +7.0 V
V
IN
DC Input Voltage (Referenced to GND) −0.5 to V
CC
+0.5 V
V
OUT
DC Output Voltage (Referenced to GND) −0.5 to V
CC
+0.5 V
I
IN
DC Input Current, per Pin ±20 mA
I
OUT
DC Output Sink/Source Current, per Pin ±50 mA
I
CC
DC V
CC
or GND Current per Output Pin ±50 mA
T
stg
Storage Temperature −65 to +150 °C
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the
Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect
device reliability.