MC74AC57 MC74ACT574

5-2

FACT DATA

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

On

Function

H

H

L

NC

Z

Hold

H

H

H

NC

Z

Hold

H

L

L

Z

Load

H

H

H

Z

Load

L

L

L

L

Data Available

L

H

H

H

Data Available

L

H

L

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

LOGIC DIAGRAM

D0

D1

D2

D3

D4

D5

D6

D7

C

D

Q

O0

O1

O2

O3

O4

O5

O6

O7

OE

CP

C

D

Q

C

D

Q

C

D

Q

C

D

Q

C

D

Q

C

D

Q

C

D

Q

Please note that this diagram is provided only for the understanding of logic

operations and should not be used to estimate propagation delays.