SN54HC640, SN74HC640

OCTAL BUS TRANSCEIVERS

WITH 3-STATE OUTPUTS

SCLS303A – JANUARY 1996 – REVISED MAY 1997

1

POST OFFICE BOX 655303

to 15 LSTTL Loads

Small-Outline (DW) and Ceramic Flat (W)

Packages, Ceramic Chip Carriers (FK), and

Standard Plastic (N) and Ceramic (J)

300-mil DIPs

description

These octal bus transceivers are designed for

asynchronous two-way communication between

data buses. These devices transmit data from the

A bus to the B bus or from the B bus to the A bus,

depending upon the level at the direction-control

(DIR) input. The output-enable (OE) input can be

used to disable the device so the buses are

effectively isolated.

The SN54HC640 is characterized for operation

over the full military temperature range of –55

°C

to 125

°C. The SN74HC640 is characterized for

operation from –40

°C to 85°C.

FUNCTION TABLE

INPUTS

OPERATION

OE

DIR

OPERATION

L

L

B data to A bus

L

HA data to B bus

H

X

Isolation

Copyright

© 1997, Texas Instruments Incorporated

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

SN54HC640 ...J OR W PACKAGE

SN74HC640 . . . DW OR N PACKAGE

(TOP VIEW)

SN54HC640 . . . FK PACKAGE

(TOP VIEW)

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2

3

4

5

6

7

8

9

10

20

19

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11

DIR

A1

A2

A3

A4

A5

A6

A7

A8

GND

OE

B1

B2

B3

B4

B5

B6

B7

B8

32

1 20 19

9 10 11 12 13

4

5

6

7

8

18

17

16

15

14

B1

B2

B3

B4

B5

A3

A4

A5

A6

A7