SN54HCT623, SN74HCT623

OCTAL BUS TRANSCEIVERS

WITH 3-STATE OUTPUTS

SCLS016B – MARCH 1984 – 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 ’HCT623 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.

The output-enable inputs 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 SN54HCT623 is characterized for operation over the full military temperature range of –55

°C to 125°C. The

SN74HCT623 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.

SN54HCT623 ...J OR W PACKAGE

SN74HCT623 . . . DW OR N PACKAGE

(TOP VIEW)

SN54HCT623 . . . 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