74VHC74 Dual D-Type Flip-Flop with Preset and Clear
October 1992
Revised March 1999
74VHC74
Dual D-Type Flip-Flop with Preset and Clear
General Description
The VHC74 is an advanced high speed CMOS Dual D-
Type Flip-Flop fabricated with silicon gate CMOS technol-
ogy. It achieves the high speed operation similar to equiva-
lent Bipolar Schottky TTL while maintaining the CMOS low
power dissipation. The signal level applied to the D input is
transferred to the Q output during the positive going transi-
tion of the CK pulse. CLR and PR are independent of the
CK and are accomplished by setting the appropriate input
LOW.
An input protection circuit ensures that 0V to 7V can be
applied to the input pins without regard to the supply volt-
age. This device can be used to interface 5V to 3V systems
and two supply systems such as battery backup. This cir-
cuit prevents device destruction due to mismatched supply
and input voltages.
Features
s
High Speed: f
MAX
=
170 MHz (typ) at T
A
=
25擄C
s
High noise immunity: V
NIH
=
V
NIL
=
28% V
CC
(min)
s
Power down protection is provided on all inputs
s
Low power dissipation: I
CC
=
2
碌A(chǔ)
(max) at T
A
=
25擄C
s
Pin and function compatible with 74HC74
Ordering Code:
Order Number
74VHC74M
74VHC74SJ
74VHC74MTC
74VHC74N
Package Number
M14A
M14D
MTC14
N14A
Package Description
14-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-120, 0.150鈥?Narrow
14-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
14-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
14-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300鈥?Wide
Surface mount packages are also available on Tape and Reel. Specify by appending the suffix letter 鈥淴鈥?to the ordering code.
Logic Symbol
IEEE/IEC
Connection Diagram
Pin Descriptions
Pin Names
D
1
, D
2
CK
1
, CK
2
CLR
1
, CLR
2
PR
1
, PR
2
Q
1
, Q
1
, Q
2
, Q
2
Description
Data Inputs
Clock Pulse Inputs
Direct Clear Inputs
Direct Preset Inputs
Output
Truth Table
Inputs
CLR
L
H
L
H
H
H
PR
H
L
L
H
H
H
D
X
X
X
L
H
X
CK
X
X
Q
L
H
L
H
Q
n
Outputs
Function
Q
H
L
H
L
Q
n
No Change
Clear
Preset
Note 1:
This configuration is nonstable; that is, it will not persist when pre-
set and clear inputs return to their inactive (HIGH) state.
X
H (Note 1) H (Note 1)
漏 1999 Fairchild Semiconductor Corporation
DS011505.prf
www.fairchildsemi.com
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