© Semiconductor Components Industries, LLC, 1999

December, 1999 – Rev. 6

1

Publication Order Number:

SN74LS640/D

SN74LS640 SN74LS641

SN74LS642 SN74LS645

Octal Bus Transceivers

These octal bus transceivers are designed for asynchronous

two-way communication between data buses. Control function

implementation minimizes external timing requirements. These

circuits allow data transmission from the A bus to B or from the B bus

to A bus depending upon the logic level of the direction control (DIR)

input. Enable input (G) can disable the device so that the buses are

effectively isolated.

DEVICE

OUTPUT

LOGIC

LS640

3-State

Inverting

LS641

Open-Collector

True

LS642

Open-Collector

Inverting

LS645

3-State

True

FUNCTION TABLE

CONTROL

INPUTS

OPERATION

INPUTS

LS640

LS641

G

DIR

LS640

LS642

LS641

LS645

L

L

B data to A bus

B data to A bus

L

H

A data to B bus

A data to B bus

H

X

Isolation

Isolation

H = HIGH Level, L = LOW Level, X = Irrelevant

Symbol

Parameter

Min

Typ

Max

Unit

Supply Voltage

4.75

5.0

5.25

V

Operating Ambient

Temperature Range

0

25

70

°C

Output Current – High

– 3.0

mA

–15

mA

Output Current – Low

24

mA

Symbol

Parameter

Min

Typ

Max

Unit

Supply Voltage

4.75

5.0

5.25

V

Operating Ambient

Temperature Range

0

25

70

°C

Output Voltage – High

5.5

V

Output Current – Low

24

mA

LOW

POWER

SCHOTTKY

Device

Package

Shipping

ORDERING INFORMATION

SN74LS640N

16 Pin DIP

1440 Units/Box

SN74LS640DW

16 Pin

SOIC

DW SUFFIX

CASE 751D

http://onsemi.com

2500/Tape & Reel

PLASTIC

N SUFFIX

CASE 738

20

1

20

1

SN74LS641N

16 Pin DIP

1440 Units/Box

SN74LS641DW

16 Pin

2500/Tape & Reel

SN74LS642N

16 Pin DIP

1440 Units/Box

SN74LS642DW

16 Pin

2500/Tape & Reel

SN74LS645N

16 Pin DIP

1440 Units/Box

SN74LS645DW

16 Pin

2500/Tape & Reel