SN54F251B, SN74F251B

1OF8 DATA SELECTORS/MULTIPLEXERS

WITH 3STATE OUTPUTS

SDFS066A − MARCH 1987 − REVISED OCTOBER 1993

Copyright

2−1

POST OFFICE BOX 655303

POST OFFICE BOX 1443

SN74F151B

System Bus

Inverted Data

Small-Outline Packages, Ceramic Chip

Carriers, and Standard Plastic and Ceramic

300-mil DIPs

description

These data selectors/multiplexers contain full

binary decoding to select one of eight data

sources

and

feature

strobe-controlled

complementary outputs. The 3-state outputs can

interface with and drive data lines of bus-

organized systems. When the strobe (G) input is

high, both outputs are in a high-impedance state

in which both the upper and lower transistors of

each totem-pole output are off, and the output

neither drives nor loads the bus significantly.

The SN54F251B is characterized for operation

over the full military temperature range of − 55

°C

to 125

°C. The SN74F251B is characterized for

operation from 0

°C to 70°C.

FUNCTION TABLE

INPUTS

OUTPUTS

SELECT

STROBE

OUTPUTS

C

B

A

STROBE

G

Y

W

X

X

X

H

Z

Z

L

LL

L

D0

D0

L

LH

L

D1

D1

L

HL

L

D2

D2

L

HH

L

D3

D3

H

LL

L

D4

D4

H

LH

L

D5

D5

H

HL

L

D6

D6

H

H

H

L

D7

D7

D0, D1, . . . D7 = the level of the respective D input.

1

2

3

4

5

6

7

8

16

15

14

13

12

11

10

9

D3

D2

D1

D0

Y

W

G

GND

D4

D5

D6

D7

A

B

C

SN54F251B ...J PACKAGE

SN74F251B ...D OR N PACKAGE

(TOP VIEW)

32

1 20 19

910 11 12 13

4

5

6

7

8

18

17

16

15

14

D5

D6

NC

D7

A

D1

D0

NC

Y

W

SN54F251B . . . FK PACKAGE

(TOP VIEW)

NC − No internal connection

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.