DM74LS74A - Fairchild Semiconductor

DM74LS74A

Dual Positive-Edge-Triggered D Flip-Flops with Preset,

Clear and Complementary Outputs

General Description

This device contains two independent

positive-edge-triggered D flip-flops with complementary out-

puts. The information on the D input is accepted by the

flip-flops on the positive going edge of the clock pulse. The

triggering occurs at a voltage level and is not directly related

to the transition time of the rising edge of the clock. The data

on the D input may be changed while the clock is low or high

without affecting the outputs as long as the data setup and

hold times are not violated. A low logic level on the preset or

clear inputs will set or reset the outputs regardless of the

logic levels of the other inputs.

Features

nAlternate military/aerospace device (54LS74) is

available. Contact a Fairchild Semiconductor Sales

Office/Distributor for specifications.

Connection Diagram

Function Table

Inputs Outputs

PR CLR CLK D Q Q

LHXX H L

HL XX L H

L L X X H (Note 1) H (Note 1)

HH ↑HH L

HH ↑LL H

HH LX Q

High Logic Level

X=Either Low or High Logic Level

L=Low Logic Level

↑=Positive-going Transition

Q0=The output logic level of Q before the indicated input conditions were established.

Note 1: This configuration is nonstable; that is, it will not persist when either the preset and/or clear inputs return to their inactive (high) level.

Dual-In-Line Package

DS006373-1

Order Number 54LS74DMQB, 54LS74FMQB, 54LS74LMQB,

DM54LS74AJ, DM54LS74AW, DM74LS74AM or DM74LS74AN

See Package Number E20A, J14A, M14A, N14A or W14B

March 1998

DM74LS74A Dual Positive-Edge-Triggered D Flip-Flops with Preset, Clear and Complementary

Outputs

Absolute Maximum Ratings (Note 2)

Supply Voltage 7V

Input Voltage 7V

Operating Free Air Temperature Range

DM54LS and 54LS −55˚C to +125˚C

DM74LS 0˚C to +70˚C

Storage Temperature Range −65˚C to +150˚C

Recommended Operating Conditions

Symbol Parameter DM54LS74A DM74LS74A Units

Min Nom Max Min Nom Max

Supply Voltage 4.5 5 5.5 4.75 5 5.25 V

High Level Input Voltage 2 2 V

Low Level Input Voltage 0.7 0.8 V

High Level Output Current −0.4 −0.4 mA

Low Level Output Current 4 8 mA

CLK

Clock Frequency (Note 4) 0 25 0 25 MHz

CLK

Clock Frequency (Note 5) 0 20 0 20 MHz

Pulse Width Clock High 18 18

(Note 4) Preset Low 15 15 ns

Clear Low 15 15

Pulse Width Clock High 25 25

(Note 5) Preset Low 20 20 ns

Clear Low 20 20

Setup Time (Notes 3, 4) 20↑20↑ns

Setup Time (Notes 3, 5) 25↑25↑ns

Hold Time (Notes 3, 6) 0↑0↑ns

Free Air Operating Temperature −55 125 0 70 ˚C

Note 2:

The “Absolute Maximum Ratings” are those values beyond which the safety of the device cannot be guaranteed. The device should not be operated at these

limits. The parametric values defined in the “Electrical Characteristics” table are not guaranteed at the absolute maximum ratings. The “Recommended Operating

Conditions” table will define the conditions for actual device operation.

Note 3: The symbol (↑) indicates the rising edge of the clock pulse is used for reference.

Note 4: CL=15 pF, RL=2kΩ,T

A=25˚C, and VCC =5V.

Note 5: CL=50 pF, RL=2kΩ,T

A=25˚C, and VCC =5V.

Note 6: TA=25˚C and VCC =5V.

Electrical Characteristics

over recommended operating free air temperature range (unless otherwise noted)

Symbol Parameter Conditions Min Typ Max Units

(Note 7)

Input Clamp Voltage V

=Min, I

=−18 mA −1.5 V

High Level Output V

=Min, I

=Max DM54 2.5 3.4 V

Voltage V

=Max, V

=Min DM74 2.7 3.4

Low Level Output V

=Min, I

=Max DM54 0.25 0.4

Voltage V

=Max, V

=Min DM74 0.35 0.5 V

=4 mA, V

=Min DM74 0.25 0.4

Input Current @Max V

=Max Data 0.1

Input Voltage V

=7V Clock 0.1 mA

Preset 0.2

Clear 0.2

High Level Input V

=Max Data 20

Current V

=2.7V Clock 20 µA

Clear 40

Preset 40

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Electrical Characteristics (Continued)

over recommended operating free air temperature range (unless otherwise noted)

Symbol Parameter Conditions Min Typ Max Units

(Note 7)

Low Level Input V

=Max Data −0.4

Current V

=0.4V Clock −0.4 mA

Preset −0.8

Clear −0.8

Short Circuit V

=Max DM54 −20 −100 mA

Output Current (Note 8) DM74 −20 −100

Supply Current V

=Max (Note 9) 4 8 mA

Note 7: All typicals are at VCC =5V, TA=25˚C.

Note 8: Not more than one output should be shorted at a time, and the duration should not exceed one second. For devices, with feedback from the outputs, where

shorting the outputs to ground may cause the outputs to change logic state an equivalent test may be performed where VO=2.25V and 2.125V for DM54 and DM74

series, respectively, with the minimum and maximum limits reduced by one half from their stated values. This is very useful when using automatic test equipment.

Note 9: With all outputs open, ICC is measured with CLOCK grounded after setting the Q and Q outputs high in turn.

Switching Characteristics

at V

=5V and T

=25˚C

From (Input) R

=2kΩ

Symbol Parameter To (Output) C

=15 pF C

=50 pF Units

Min Max Min Max

MAX

Maximum Clock Frequency 25 20 MHz

PLH

Propagation Delay Time Clock to 25 35 ns

Low to High Level Output Q or Q

PHL

Propagation Delay Time Clock to 30 35 ns

High to Low Level Output Q or Q

PLH

Propagation Delay Time Preset 25 35 ns

Low to High Level Output to Q

PHL

Propagation Delay Time Preset 30 35 ns

High to Low Level Output to Q

PLH

Propagation Delay Time Clear 25 35 ns

Low to High Level Output to Q

PHL

Propagation Delay Time Clear 30 35 ns

High to Low Level Output to Q

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Physical Dimensions inches (millimeters) unless otherwise noted

Ceramic Leadless Chip Carrier Package (E)

Order Number 54LS74LMQB

Package Number E20A

14-Lead Ceramic Dual-In-Line Package (J)

Order Number 54LS74DMQB or DM54LS74AJ

Package Number J14A

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Physical Dimensions inches (millimeters) unless otherwise noted (Continued)

14-Lead Small Outline Molded Package (M)

Order Number DM74LS74AM

Package Number M14A

14-Lead Molded Dual-In-Line Package (N)

Order Number DM74LS74AN

Package Number N14A

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Physical Dimensions inches (millimeters) unless otherwise noted (Continued)

LIFE SUPPORT POLICY

FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DE-

VICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMI-

CONDUCTOR CORPORATION. As used herein:

1. Life support devices or systems are devices or sys-

tems which, (a) are intended for surgical implant into

the body, or (b) support or sustain life, and (c) whose

failure to perform when properly used in accordance

with instructions for use provided in the labeling, can

be reasonably expected to result in a significant injury

to the user.

2. A critical component in any component of a life support

device or system whose failure to perform can be rea-

sonably expected to cause the failure of the life support

device or system, or to affect its safety or effectiveness.

Fairchild Semiconductor

Corporation

Americas

Customer Response Center

Tel: 1-888-522-5372

www.fairchildsemi.com

Fairchild Semiconductor

Europe Fax: +49 (0) 1 80-530 85 86

Email: europe.support@nsc.com

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Fairchild Semiconductor

Hong Kong Ltd.

13th Floor, Straight Block,

Ocean Centre, 5 Canton Rd.

Tsimshatsui, Kowloon

Hong Kong

Tel: +852 2737-7200

Fax: +852 2314-0061

National Semiconductor

Japan Ltd.

Tel: 81-3-5620-6175

Fax: 81-3-5620-6179

14-Lead Ceramic Flat Package (W)

Order Number 54LS74FMQB or DM54LS74AW

Package Number W14B

DM74LS74A Dual Positive-Edge-Triggered D Flip-Flops with Preset, Clear and Complementary

Outputs

Fairchild does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and Fairchild reserves the right at any time without notice to change said circuitry and specifications.