SN54ALS191A, SN74ALS191A

SYNCHRONOUS 4BIT UP/DOWN BINARY COUNTERS

SDAS210C − DECEMBER 1982 − REVISED JULY 1996

5

POST OFFICE BOX 655303

POST OFFICE BOX 1443

7 V

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

7 V

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

−55

°C to 125°C

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

SN74ALS191A

0

°C to 70°C

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

−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

SN54ALS191A

SN74ALS191A

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

− 0.4

− 0.4

mA

IOL

Low-level output current

4

8

mA

fclock

Clock frequency

0

20

0

30

MHz

tw

Pulse duration

CLK high or low

20

16.5

ns

tw

Pulse duration

LOAD low

25

20

ns

Data before LOAD

↑

25

20

tsu

Setup time

CTEN before CLK

↑

45

20

ns

tsu

Setup time

D/U before CLK

↑

30

20

ns

LOAD inactive before CLK

↑

20

20

Data after LOAD

↑

5

5

th

Hold time

CTEN after CLK

↑

0

0

ns

D/U after CLK

↑

0

0

ns

TA

Operating free-air temperature

−55

125

0

70

°C