5-341

FAST AND LS TTL DATA

PRESETTABLE BCD/DECADE

UP/DOWN COUNTERS

PRESETTABLE 4-BIT BINARY

UP/DOWN COUNTERS

The SN54 / 74LS190 is a synchronous UP/ DOWN BCD Decade (8421)

Counter and the SN54/ 74LS191 is a synchronous UP / DOWN Modulo-16

Binary Counter. State changes of the counters are synchronous with the

LOW-to-HIGH transition of the Clock Pulse input.

An asynchronous Parallel Load (PL) input overrides counting and loads the

data present on the Pn inputs into the flip-flops, which makes it possible to use

the circuits as programmable counters. A Count Enable (CE) input serves as

the carry / borrow input in multi-stage counters. An Up / Down Count Control

(U/D) input determines whether a circuit counts up or down. A Terminal Count

(TC) output and a Ripple Clock (RC) output provide overflow/underflow

indication and make possible a variety of methods for generating

carry / borrow signals in multistage counter applications.

NOTE:

The Flatpak version

has the same pinouts

(Connection Diagram) as

the Dual In-Line Package.

CONNECTION DIAGRAM DIP (TOP VIEW)

14

13

12

11

10

9

1

2

3

4

5

6

7

16

15

8

VCC

P1

P0

CP

RC

TC

P2

PL

P3

Q1

Q0

CE

U/D

Q2

Q3 GND

PIN NAMES

LOADING (Note a)

HIGH

LOW

CE

CP

U / D

PL

Pn

Qn

RC

TC

Count Enable (Active LOW) Input

Clock Pulse (Active HIGH going edge) Input

Up/Down Count Control Input

Parallel Load Control (Active LOW) Input

Parallel Data Inputs

Flip-Flop Outputs (Note b)

Ripple Clock Output (Note b)

Terminal Count Output (Note b)

1.5 U.L.

0.5 U.L.

0.5 U.L.

0.5 U.L.

0.5 U.L.

10 U.L.

10 U.L.

10 U.L.

0.7 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.

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)

SN54/74LS190

SN54/74LS191

PRESETTABLE BCD / DECADE

UP / DOWN COUNTERS

PRESETTABLE 4-BIT BINARY

UP / DOWN 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

LOGIC SYMBOL

VCC = PIN 16

GND = PIN 8

5

4

14

3 2 6 7

13

9

10

1

15

11

U/D

CP

Q0 Q1 Q2 Q3

TC

P3

P2

P1

P0

PL

CE

RC

12