SL74HC161

System Logic

Semiconductor

SLS

Presettable Counters

High-Performance Silicon-Gate CMOS

The SL74HC161 is identical in pinout to the LS/ALS161. The device

inputs are compatible with standard CMOS outputs; with pullup

resistors, they are compatible with LS/ALSTTL outputs.

The SL74HC161 is programmable 4-bit synchronous counter that

feature parallel Load, asynchronous Reset, a Carry Output for

cascading and count-enable controls.

The SL74HC161 is binary counter with asynchronous Reset.

• Outputs Directly Interface to CMOS, NMOS, and TTL

• Operating Voltage Range: 2.0 to 6.0 V

• Low Input Current: 1.0 µA

• High Noise Immunity Characteristic of CMOS Devices

ORDERING INFORMATION

SL74HC161N Plastic

SL74HC161D SOIC

° to 125° C for all packages

LOGIC DIAGRAM

PIN 8 = GND

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

PIN ASSIGNMENT