© Semiconductor Components Industries, LLC, 2006

July, 2006 − Rev. 7

1

Publication Order Number:

SN74LS168/D

SN74LS168

BCD DECADE

16 BINARY SYNCHRONOUS

BI-DIRECTIONAL

COUNTERS

The SN54/74LS168 is a fully synchronous 4-stage up/down

counter featuring a preset capability for programmable operation,

carry lookahead for easy cascading and a U/D input to control the

direction of counting. The SN54/74LS168 counts in a BCD decade (8,

4, 2, 1) sequence. All state changes, whether in counting or parallel

NOTE:

The Flatpak version

has the same pinouts

(Connection Diagram) as the Dual

In-Line Package.

14

13

12

11

10

9

123

45

6

7

16

15

8

U/D

TC

CET

PE

CP

CEP GND

CONNECTION DIAGRAM DIP (TOP VIEW)

PIN NAMES

LOADING (Note a)

HIGH

LOW

CEP

CET

CP

PE

U/D

TC

Count Enable Parallel (Active LOW) Input

Count Enable Trickle (Active LOW) Input

Clock Pulse (Active positive going edge) Input

Parallel Enable (Active LOW) Input

Up-Down Count Control Input

Parallel Data Inputs

Flip-Flop Outputs

Terminal Count (Active LOW) Output

0.5 U.L.

1.0 U.L.

0.5 U.L.

0.5 U.L.

0.5 U.L.

0.5 U.L.

10 U.L.

10 U.L.

0.25 U.L.

0.5 U.L.

0.25 U.L.

0.25 U.L.

0.25 U.L.

0.25 U.L.

5 (2.5) U.L.

5 (2.5) U.L.

NOTES:

a. 1 TTL Unit Load (U.L.) = 40 μA HIGH/1.6 mA LOW.

b. The Output LOW drive factor is 2.5 U.L. for Military (54) and 5 U.L. for Commercial (74)

Temperature Ranges.

http://onsemi.com

BCD DECADE

16 BINARY SYNCHRONOUS

BI-DIRECTIONAL COUNTERS

LOW POWER SCHOTTKY

J SUFFIX

CERAMIC

CASE 620-09

N SUFFIX

PLASTIC

CASE 648-08

16

1

16

1

ORDERING INFORMATION

SN54LSXXXJ

Ceramic

SN74LSXXXN

Plastic

SN74LSXXXD

SOIC

16

1

D SUFFIX

SOIC

CASE 751B-03

93 4

5 6

7

10

2

15

14 13 12 11

CEP

CET

CP

TC

GND = PIN 8

1

U/D

LOGIC SYMBOL