74ABT377 Octal D-Type Flip-Flop with Clock Enable
January 1993
Revised November 1999
74ABT377
Octal D-Type Flip-Flop with Clock Enable
General Description
The ABT377 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.
The register is fully edge-triggered. The state of each D
input, one setup time before the LOW-to-HIGH clock transi-
tion, is transferred to the corresponding flip-flop鈥檚 Q output.
The CE input must be stable only one setup time prior to
the LOW-to-HIGH clock transition for predictable operation.
Features
s
Clock enable for address and data synchronization
applications
s
Eight edge-triggered D-type flip-flops
s
Buffered common clock
s
See ABT273 for master reset version
s
See ABT373 for transparent latch version
s
See ABT374 for 3-STATE version
s
Output sink capability of 64 mA, source capability
of 32 mA
s
Guaranteed latchup protection
s
High impedance glitch free bus loading during entire
power up and power down cycle
s
Non-destructive hot insertion capability
s
Disable time less than enable time to avoid bus
contention
Ordering Code:
Order Number
74ABT377CSC
74ABT377CSJ
74ABT377CMSA
74ABT377CMTC
Package Number
M20B
M20D
MSA20
MTC20
Package Description
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300鈥?Wide Body
20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
20-Lead Shrink Small Outline Package (SSOP), EIAJ TYPE II, 5.3mm Wide
20-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
Devices also available in Tape and Reel. Specify by appending the suffix letter 鈥淴鈥?to the ordering code.
Connection Diagram
Pin Descriptions
Pin Names
D
0
鈥揇
7
CE
CP
Q
0
鈥換
7
Descriptions
Data Inputs
Clock Enable (Active LOW)
Clock Pulse Input
Data Outputs
Truth Table
Operating Mode
CP
Load 鈥?鈥?/div>
Load 鈥?鈥?/div>
Hold
(Do Nothing)
Inputs
Output
D
n
h
I
X
X
Q
n
H
L
No Change
No Change
X
CE
I
I
h
H
H
=
HIGH Voltage Level
L
=
LOW Voltage Level
X
=
Immaterial
=
LOW-to-HIGH Clock Transition
h
=
HIGH Voltage Level one setup time prior to the
LOW-to-HIGH Clock Transition
I
=
LOW Voltage Level one setup time prior to the
LOW-to-HIGH Clock Transition
漏 1999 Fairchild Semiconductor Corporation
DS011550
www.fairchildsemi.com
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