SN54HC623, SN74HC623

OCTAL BUS TRANSCEIVERS

WITH 3-STATE OUTPUTS

SCLS149B – DECEMBER 1982 – 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. The control-function implementation

allows for maximum flexibility in timing.

The ’HC623 allow data transmission from the

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

depending

upon

the

logic

levels

at

the

output-enable (OEAB and OEBA) inputs.

OEAB and OEBA disable the device so that the

buses are effectively isolated. The dual-enable

configuration gives the transceivers the capability

to store data by simultaneously enabling OEAB

and OEBA. Each output reinforces its input in this

transceiver configuration. When both OEAB and

OEBA are enabled and all other data sources to

the two sets of bus lines are in the high-impedance

state, both sets of bus lines (16 total) remain at

their last states. The 8-bit codes appearing on the

two sets of buses are identical.

The SN54HC623 is characterized for operation over the full military temperature range of –55

°C to 125°C. The

SN74HC623 is characterized for operation from –40

°C to 85°C.

FUNCTION TABLE

INPUTS

OPERATION

OEBA

OEAB

OPERATION

L

L

B data to A bus

H

H

A data to B bus

H

L

Isolation

L

H

B data to A bus,

A data to B bus

Copyright

© 1997, Texas Instruments Incorporated

UNLESS OTHERWISE NOTED this document contains PRODUCTION

DATA information 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.

SN54HC623 ...J OR W PACKAGE

SN74HC623 . . . DW OR N PACKAGE

(TOP VIEW)

SN54HC623 . . . FK PACKAGE

(TOP VIEW)

1

2

3

4

5

6

7

8

9

10

20

19

18

17

16

15

14

13

12

11

OEAB

A1

A2

A3

A4

A5

A6

A7

A8

GND

OEBA

B1

B2

B3

B4

B5

B6

B7

B8

32 1 20 19

910 11 1213

4

5

6

7

8

18

17

16

15

14

B1

B2

B3

B4

B5

A3

A4

A5

A6

A7