SN54ALS245A, SN54AS245, SN74ALS245A, SN74AS245

OCTAL BUS TRANSCEIVERS

WITH 3-STATE OUTPUTS

SDAS272A – NOVEMBER 1994 – REVISED JANUARY 2003

2

POST OFFICE BOX 655303

description/ordering information(continued)

These octal bus transceivers are designed for asynchronous two-way communication between data buses. The

control-function implementation minimizes external timing requirements.

The 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 level at the direction-control (DIR) input. The output-enable (OE) input can be used to disable the

device so that the buses are effectively isolated.

The -1 version of the SN74ALS245A is identical to the standard version, except that the recommended

FUNCTION TABLE

INPUTS

OPERATION

OE

DIR

OPERATION

L

L

B data to A bus

L

H

A data to B bus

H

X

Isolation

logic diagram, each gate (positive logic)

DIR

OE

A1

B1

1

2

18

19

To Seven Other Channels

absolute

maximum

ratings

over

operating

free-air

temperature

range

(SN54ALS245A,

7 V

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7 V

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

I/O ports

5.5 V

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Package thermal impedance,

70

°C/W

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

DW package

58

°C/W

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

N package

69

°C/W

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

NS package

60

°C/W

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Storage temperature range

–65

°C to 150°C

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

† Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and

functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not

implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

NOTE 1: The package thermal impedance is calculated in accordance with JESD 51-7.