SL74LS161

System Logic

Semiconductor

SLS

FUNCTION TABLE

Inputs

Outputs

Reset

Load

Enable

P

Enable

T

Clock

Q0

Q1

Q2

Q3

Function

L

X

X

X

X

L

L

L

L

Reset to “0”

H

L

X

X

P0

P1

P2

P3

Preset Data

H

H

X

L

No change

No count

H

H

L

X

No change

No count

H

H

H

H

Count up

Count

H

X

X

X

No change

No count

X=don’t care

P0,P1,P2,P3 = logic level of Data inputs

Ripple Carry Out = Enable T

• Q0 • Q1 • Q2 • Q3

MAXIMUM RATINGS

*

Symbol

Parameter

Value

Unit

Supply Voltage

7.0

V

Input Voltage

7.0

V

Output Voltage

5.5

V

Tstg

Storage Temperature Range

-65 to +150

°C

Functional operation should be restricted to the Recommended Operating Conditions.

RECOMMENDED OPERATING CONDITIONS

Symbol

Parameter

Min

Max

Unit

Supply Voltage

4.75

5.25

V

High Level Input Voltage

2.0

V

Low Level Input Voltage

0.8

V

High Level Output Current

-0.4

mA

Low Level Output Current

8.0

mA

Clock frequency

0

25

MHz

Width of clock pulse

25

ns

Width of reset pulse

20

ns

Data inputs P0, P1, P2, P3

20

Setup time

Enable P or T

20

ns

Load

20

Hold time at any input

3

ns

Ambient Temperature Range

0

+70

°C