DM74LS191N Fairchild Semiconductor, DM74LS191N Datasheet

DM74LS191N

Manufacturer Part Number

DM74LS191N

Description

IC COUNTER BINARY UP/DOWN 16-DIP

Manufacturer

Fairchild Semiconductor

Series

74LSr

Datasheet

1.DM74LS191N.pdf (6 pages)

Specifications of DM74LS191N

Logic Type

Binary Counter

Direction

Up, Down

Number Of Elements

Number Of Bits Per Element

Timing

Synchronous

Count Rate

20MHz

Trigger Type

Positive Edge

Voltage - Supply

4.75 V ~ 5.25 V

Operating Temperature

0°C ~ 70°C

Mounting Type

Through Hole

Package / Case

16-DIP (0.300", 7.62mm)

Lead Free Status / RoHS Status

Contains lead / RoHS non-compliant

Reset

Other names

74LS191
74LS191N

Current page: 1 of 6
Download datasheet (76Kb)

Order Number

DM74LS191M

DM74LS191N

DM74LS191

Synchronous 4-Bit Up/Down Counter with Mode Control

General Description

The DM74LS191 circuit is a synchronous, reversible, up/

down counter. Synchronous operation is provided by hav-

ing all flip-flops clocked simultaneously, so that the outputs

change simultaneously when so instructed by the steering

logic. This mode of operation eliminates the output count-

ing spikes normally associated with asynchronous (ripple

clock) counters.

The outputs of the four master-slave flip-flops are triggered

on a LOW-to-HIGH level transition of the clock input, if the

enable input is LOW. A HIGH at the enable input inhibits

counting. Level changes at either the enable input or the

down/up input should be made only when the clock input is

HIGH. The direction of the count is determined by the level

of the down/up input. When LOW, the counter counts up

and when HIGH, it counts down.

The counter is fully programmable; that is, the outputs may

be preset to either level by placing a LOW on the load input

and entering the desired data at the data inputs. The output

will change independent of the level of the clock input. This

feature allows the counters to be used as modulo-N divid-

ers by simply modifying the count length with the preset

inputs.

The clock, down/up, and load inputs are buffered to lower

the drive requirement; which significantly reduces the num-

ber of clock drivers, etc., required for long parallel words.

Ordering Code:

Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.

Package Number

M16A

N16E

16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150” Narrow Body

16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300” Wide

DS006405.prf

Two outputs have been made available to perform the cas-

cading function: ripple clock and maximum/minimum count.

The latter output produces a high-level output pulse with a

duration approximately equal to one complete cycle of the

clock when the counter overflows or underflows. The ripple

clock output produces a low-level output pulse equal in

width to the low-level portion of the clock input when an

overflow or underflow condition exists. The counters can be

easily cascaded by feeding the ripple clock output to the

enable input of the succeeding counter if parallel clocking

is used, or to the clock input if parallel enabling is used.

The maximum/minimum count output can be used to

accomplish look-ahead for high-speed operation.

Features

Counts binary

Single down/up count control line

Count enable control input

Ripple clock output for cascading

Asynchronously presettable with load control

Parallel outputs

Cascadable for n-bit applications

Average propagation delay 20 ns

Typical clock frequency 25 MHz

Typical power dissipation 100 mW

Package Description

August 1986

Revised February 1999

www.fairchildsemi.com

Related parts for DM74LS191N

DM74LS191N Summary of contents

Page 1

... DM74LS191M M16A 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150” Narrow Body DM74LS191N N16E 16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300” Wide Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code. ...

Page 2

Connection Diagram Timing Diagram www.fairchildsemi.com 2 ...

Page 3

Logic Diagram Pin (16 Pin (8) GND CC 3 www.fairchildsemi.com ...

Page 4

Absolute Maximum Ratings Storage Temperature Range Input Voltage Operating Free Air Temp. Range Supply Voltage Recommended Operating Conditions Symbol V Supply Voltage CC V HIGH Level Input Voltage IH V LOW Level Input Voltage IL I HIGH Level Output Current ...

Page 5

AC Electrical Characteristics Symbol Parameter f Maximum Clock MAX Frequency t Propagation Delay Time PLH LOW-to-HIGH Level Output t Propagation Delay Time PHL HIGH-to-LOW Level Output t Propagation Delay Time PLH LOW-to-HIGH Level Output t Propagation Delay Time PHL HIGH-to-LOW ...

Page 6

Physical Dimensions inches (millimeters) unless otherwise noted 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS012, 0.150” Narrow Body 16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 300” Wide LIFE SUPPORT POLICY FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS ...

Related keywords

dm74ls193
dm74ls191
dm74ls191m
dm74ls193n
dm74ls191n
DM74LS191N datasheet
DM74LS191N data sheet
DM74LS191N pdf datasheet
DM74LS191N component
DM74LS191N part
DM74LS191N distributor
DM74LS191N RoHS
DM74LS191N datasheet download