July 1997

Revised April 1999

© 1999 Fairchild Semiconductor Corporation

DS500026.prf

www.fairchildsemi.com

74VHCT74A

Dual D-Type Flip-Flop with Preset and Clear

General Description

The VHCT74A 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

transition of the CK pulse. CLR and PR are independent of

the CK and are accomplished by setting the appropriate

input LOW.

Protection circuits ensure that 0V to 7V can be applied to

the input pins without regard to the supply voltage and to

device destruction due to mismatched supply and input/

output voltages. This device can be used to interface 3V to

5V systems and two supply systems such as battery

backup.

Features

s Power down protection is provided on all inputs and

outputs

s Low power dissipation:

s Pin and function compatible with 74HCT74

Ordering Code:

Surface mount packages are also available on Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.

Logic Symbol

IEEE/IEC

Pin Descriptions

Connection Diagram

Truth Table

Order Number

Package Number

Package Description

74VHCT74AM

M14A

14-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-120, 0.150 Narrow

74VHCT74ASJ

M14D

14-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide

74VHCT74AMTC

MTC14

14-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide

74VHCT74AN

N14A

14-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide

Pin Names

Description

Data Inputs

Clock Pulse Inputs

Direct Clear Inputs

Direct Preset Inputs

Outputs

Inputs

Outputs

Function

CLR

PR

DCK

Q

Q

L

H

X

X

L

H

Clear

HL

X

X

H

L

Preset

LL

X

X

H

H

HH

L



LH

HH

H



HL

HH

X



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