SN54ALS251, SN74ALS251

1-OF-8 DATA SELECTORS/MULTIPLEXERS

WITH 3-STATE OUTPUTS

SDAS215A – APRIL 1982 – REVISED DECEMBER 1994

4

POST OFFICE BOX 655303

switching characteristics (see Figure 1)

PARAMETER

FROM

(INPUT)

TO

(OUTPUT)

VCC = 4.5 V to 5.5 V,

CL = 50 pF,

R1 = 500

R2 = 500

TA = MIN to MAX†

UNIT

SN54ALS251

SN74ALS251

MIN

MAX

MIN

MAX

tPLH

ABor C

Y

1

21

5

18

ns

tPHL

A, B, or C

Y

7

34

8

24

ns

tPLH

ABor C

W

5

38

8

24

ns

tPHL

A, B, or C

W

7

26

7

23

ns

tPLH

An D

Y

2

15

2

10

ns

tPHL

Any D

Y

3

23

3

15

ns

tPLH

An D

W

3

25

3

15

ns

tPHL

Any D

W

3

20

3

15

ns

tPZH

OE

Y

3

21

3

15

ns

tPZL

OE

Y

3

19

3

15

ns

tPZH

OE

W

3

21

3

15

ns

tPZL

OE

W

3

19

3

15

ns

tPZH

OE

Y

2

12

2

10

ns

tPZL

OE

Y

1

18

1

10

ns

tPZH

OE

W

2

12

2

10

ns

tPZL

OE

W

1

18

1

10

ns

† For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.