February 1999
54AC377 • 54ACT377
Octal D Flip-Flop with Clock Enable
n Ideal for addressable register applications
n Clock enable for address and data synchronization
applications
n Eight edge-triggered D flip-flops
n Buffered common clock
General Description
The ’AC/’ACT377 has eight edge-triggered, D-type flip-flops
with individual D inputs and Q outputs. The common buff-
ered Clock (CP) input loads all flip-flops simultaneously,
when the Clock Enable (CE) is LOW.
n Outputs source/sink 24 mA
n See ’273 for master reset version
n See ’373 for transparent latch version
n See ’374 for TRI-STATE® version
n ’ACT377 has TTL-compatible inputs
n Standard Microcircuit Drawing (SMD)
— ’AC377: 5962-88702
The register is fully edge-triggered. The state of each D in-
put, one setup time before the LOW-to-HIGH clock transi-
tion, is transferred to the corresponding flip-flop’s Q output.
The CE input must be stable only one setup time prior to the
LOW-to-HIGH clock transition for predictable operation.
Features
n ICC reduced by 50%
— ’ACT377: 5962-87697
Logic Symbols
IEEE/IEC
DS100290-1
DS100290-2
Pin
Description
Names
D0–D7
CE
Data Inputs
Clock Enable (Active LOW)
Data Outputs
Q0–Q7
CP
Clock Pulse Input
TRI-STATE® is a registered trademark of National Semiconductor Corporation.
FACT® is a registered trademark of Fairchild Semiconductor Corporation.
© 1999 National Semiconductor Corporation
DS100290
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