SN54BCT620A, SN74BCT620A

OCTAL BUS TRANSCEIVERS

WITH 3STATE OUTPUTS

SCBS001B − SEPTEMBER 1987 − REVISED NOVEMBER 1993

Copyright

2−1

POST OFFICE BOX 655303

POST OFFICE BOX 1443

Per MIL-STD-883C, Method 3015

Small-Outline (DW) Packages, Ceramic

Chip Carriers (FK) and Flatpacks (W), and

Plastic and Ceramic 300-mil DIPs (J, N)

description

The

′BCT620A bus transceiver is designed for

asynchronous

communication

between

data

buses. The control function implementation allows

for maximum flexibility in timing. The

′BCT620A

provides inverted data at its outputs.

These devices 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 can be used to disable

the device so that the buses are effectively

isolated. The dual-enable configuration gives the

transceivers the capability of storing data by

simultaneously enabling OEAB and OEBA. When

both OEAB and OEBA are enabled and all other

data sources to the two sets of bus lines are at high

impedance, both sets of bus lines (16 in all) will

remain at their last states. In this way, each output

reinforces its input in this configuration.

The SN54BCT620A is characterized for operation

over the full military temperature range of − 55

°C

to 125

°C. The SN74BCT620A is characterized for

operation from 0

°C to 70°C.

FUNCTION TABLE

INPUTS

OPERATION

OEBA

OEAB

OPERATION

L

L

B data to A bus

L

H

B data to A bus,

A data to B bus

H

L

Isolation

H

H

A data to B bus

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

SN54BCT620A ...J OR W PACKAGE

SN74BCT620A . . . DW OR N PACKAGE

(TOP VIEW)

3

2

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

SN54BCT620A . . . FK PACKAGE

(TOP VIEW)

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.