SN54ALS640B, SN54AS640, SN74ALS640B, SN74AS640

OCTAL BUS TRANSCEIVERS

WITH 3-STATE OUTPUTS

SDAS122A – DECEMBER 1983 – REVISED JANUARY 1995

2

POST OFFICE BOX 655303

logic diagram (positive logic)

B2

17

B3

16

B4

15

A5

6

A6

7

A7

8

A8

9

A2

3

A3

4

A4

5

OE

A1

2

G3

19

3 EN2 [AB]

B5

14

B6

13

B7

12

B8

11

B1

18

3 EN1 [BA]

1

DIR

1

2

A1

B1

19

1

18

2

OE

DIR

To Seven Other Transceivers

† This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.

7 V

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

7 V

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

I/O ports

5.5 V

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

– 55

°C to 125°C

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

SN74ALS640B

0

°C to 70°C

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

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.

recommended operating conditions

SN54ALS640B

SN74ALS640B

UNIT

MIN

NOM

MAX

MIN

NOM

MAX

UNIT

VCC

Supply voltage

4.5

5

5.5

4.5

5

5.5

V

VIH

High-level input voltage

2

2

V

VIL

Low-level input voltage

0.7

0.8

V

IOH

High-level output current

–12

–15

mA

IOL

Low level output current

12

24

mA

IOL

Low-level output current

48§

mA

TA

Operating free-air temperature

–55

125

0

70

°C

§ Applies only to the -1 version and only if VCC is between 4.75 V and 5.25 V