mm74hct191 National Semiconductor Corporation, mm74hct191 Datasheet

mm74hct191

Manufacturer Part Number

mm74hct191

Description

Mm54hct190/mm74hct190 Synchronous Decade Up/ Down Counters With Mode Control. Mm54hct191/ Mm74hct191 Synchronous Binary Up/down Counters With Mode Control

Manufacturer

National Semiconductor Corporation

Datasheet

1.MM74HCT191.pdf (8 pages)

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C 1995 National Semiconductor Corporation

MM54HCT190 MM74HCT190 Synchronous Decade Up

Down Counters with Mode Control MM54HCT191

MM74HCT191 Synchronous Binary Up Down Counters

with Mode Control

General Description

These high speed synchronous counters utilize advanced

silicon-gate CMOS technology They possess the high noise

immunity and low power consumption of CMOS technology

along with the speeds of low power Schottky TTL These

circuits are synchronous reversible up down counters The

MM54HCT191 MM74HCT191 are 4-bit binary counters and

the MM54HCT190 MM74HCT190 are BCD counters

Synchronous operation is provided by having all flip-flops

clocked simultaneously so that the outputs change simulta-

neously when so instructed by the steering logic This mode

of operation eliminates the output counting 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 count-

ing 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

These counters are 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 in-

put This feature allows the counters to be used as divide by

N dividers by simply modifying the count length with the

preset inputs

Connection Diagram

Dual-In-Line Package

TL F 5744

TL F 5744 – 1

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 accom-

plish look-ahead for high speed operation

MM54HCT MM74HCT devices are intended to interface be-

tween TTL and NMOS components and standard CMOS

devices These parts are also plug-in replacements for LS-

TTL devices can be used to reduce power consumption in

existing designs

Features

Truth Table

Load

Level changes on Enable or Down Up can be made

regardless of the level of the clock

Low quiescent supply current 80 mA maximum

(74HCT Series)

Low input current 1 mA maximum

TTL compatible inputs

Enable

Order Number MM54HCT190 191

or MM74HCT190 191

Down

Clock

RRD-B30M105 Printed in U S A

Count Down

No Change

January 1988

Function

Count Up

Load

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mm74hct191 Summary of contents

Page 1

... CMOS technology along with the speeds of low power Schottky TTL These circuits are synchronous reversible up down counters The MM54HCT191 MM74HCT191 are 4-bit binary counters and the MM54HCT190 MM74HCT190 are BCD counters Synchronous operation is provided by having all flip-flops ...

Page 2

Absolute Maximum Ratings If Military Aerospace specified devices are required please contact the National Semiconductor Sales Office Distributors for availability and specifications Supply Voltage ( Input Voltage ( ...

Page 3

AC Electrical Characteristics Symbol Parameter f Maximum Clock Frequency MAX t t Maximum Propagation PLH PHL Delay Time t t Maximum Propagation PLH PHL Delay Time t t Maximum Propagation PLH PHL Delay Time t t Maximum Propagation PLH PHL ...

Page 4

AC Electrical Characteristics From Symbol Parameter Input f Maximum Clock MAX Frequency t t Maximum Propa- Load PLH PHL gation Delay Time t t Maximum Propa- Data A PLH PHL gation Delay Time Maximum Propa- ...

Page 5

Timing Diagrams ’HCT190 Synchronous Decade Counters Typical Load Count and Inhibit Sequences Sequence (1) Load (preset) to BCD seven (2) Count up to eight nine zero one and two ’HCT191 Synchronous Binary Counters Typical Load Count and Inhibit Sequence Sequence ...

Page 6

Logic Diagram ’HCT191 5744 – 3 ...

Page 7

Logic Diagram (Continued) ’HCT190 Decade Counters 5744 – 7 ...

Page 8

... Physical Dimensions inches (millimeters) Order Number MM54HCT191J or MM74HCT191J LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL SEMICONDUCTOR CORPORATION As used herein 1 Life support devices or systems are devices or ...

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