ST M74HC191 User Manual

M74HC191

4 BIT SYNCHRONOUS UP/DOWN COUNTERS

■ HIGH SPEED :

f

= 61 MHz (TYP.) at VCC = 6V

MAX

■ LOW POWER DISSIPATION:

I

=4µA(MAX.) at TA=25°C

CC

■ HIGH NOISE IMMUNITY:

V

= V

NIH

■ SYMMETRICAL OUTPUT IMPEDANCE:

|I

| = IOL = 4mA (MIN)

OH

■ BALANCED PROPAGATION DELAYS:

t

≅ t

PLH

■ WIDE OPERATING VOLTAGE RANGE:

V

(OPR) = 2V to 6V

CC

■ PIN AND FUNCTION COMPATIBLE WITH

= 28 % VCC (MIN.)

NIL

PHL

74 SERIES 191

DESCRIPTION

The M74HC191 is an high speed CMOS 4-BIT SYNCHRONOUS UP/DOWN COUNTER fabricated with silicon gate C

2

MOS technology. State changes of the counter are synchronous with the LOW-to-HIGH transition of the Clock Pulse Input. An asynchronous parallel load input overrides counting and loads the dat a pres ent on th e DA TA inputs into the flip-flops, which makes it possible to use the circuits as programmable counters. A count enable input serves as the carry/borrow

TSSOPDIP SOP

ORDER CODES

PACKAGE TUBE T & R

DIP M74HC191B1R

SOP M74HC191M1R M74HC191RM13TR

TSSOP M74HC191TTR

input in multi-stage counters. Control input, Down/ Up

, determines whether a circuit counts up or down. A MAX/MIN output and a Ripple Clock output provide overflow/underflow indication and make possible a variety of methods for generating carry/borrow signals in multi-stage counter applications. All inputs are equipped with protection circuits against static discharge and transient excess voltage.

PIN CONNECTION AND IEC LOGIC SYMBOLS

1/14August 2001

M74HC191

INPUT AND OUTPUT EQUIVALENT CIRCUIT PIN DESCRIPTION

PIN No SYMBOL NAME AND FUNCTION

3, 2, 6, 7 QA to QD Flip-Flop Outputs

4 ENABLE

5U 11 LOAD Load Input (Active LOW) 12 MA/MI OUT Terminal Count Output

13 RC

14 CLOCK

15, 1, 10, 9 DA to DD Data Inputs

8 GND Ground (0V) 16 Vcc Positive Supply Voltage

TRUTH TABLE

/D Parallel Data Input

Count Enable Input (Active LOW)

Ripple Clock Output (Active LOW)

Clock Input (LOW to HIGH, edge triggered)

INPUTS OUTPUTS

LOAD

L X X X a b c d PRESET DATA

H L L UP COUNT UP COUNT H L H DOWN COUNT DOWN COUNT H H X NO CHANGE NO COUNT H X X NO CHANGE NO COUNT

X : Don’t Care a - d : The leve l of s teady state inputs a through d respec tively

ENABLE D/U CLOCKQAQBQCQD

FUNCTION

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LOGIC DIAGRAM

M74HC191

This log i c diagram has not be used to esti m ate propagation delays

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M74HC191

TIMING CHART

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Value Unit

V

I

OK

I

or I

CC

P

T

Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is not implied

(*) 500mW at 65

Supply Voltage

CC

DC Input Voltage -0.5 to VCC + 0.5

I

DC Output Voltage -0.5 to VCC + 0.5

O

DC Input Diode Current

IK

DC Output Diode Current DC Output Current

O

DC VCC or Ground Current

GND

Power Dissipation

D

Storage Temperature

stg

Lead Temperature (10 sec)

L

°C; derate to 300mW by 10mW/°C from 65°C to 85°C

-0.5 to +7 V V V

± 20 mA ± 20 mA ± 25 mA ± 50 mA

500(*) mW

-65 to +150 °C

300 °C

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M74HC191

RECOMMENDED OPERATING CONDITIONS

Symbol Parameter Value Unit

V

T

t

r

DC SPECIFICATIONS

Symbol Parameter

V

IH

V

IL

V

OH

V

OL

I

CC

Supply Voltage

CC

Input Voltage 0 to V

I

Output Voltage 0 to V

O

Operating Temperature

op

Input Rise and Fall Time VCC = 2.0V

, t

f

V V

CC CC

= 4.5V = 6.0V

Test Condition Value

= 25°C

T

A

Min. Typ. Max. Min. Max. Min. Max.

High Level Input

V

CC

(V)

2.0 1.5 1.5 1.5

Voltage

6.0 4.2 4.2 4.2

Low Level Input

2.0 0.5 0.5 0.5

Voltage

6.0 1.8 1.8 1.8

High Level Output Voltage

Low Level Output Voltage

Input Leakage Current

Quiescent Supply Current

2.0

4.5

6.0

4.5

6.0

2.0

4.5

6.0

4.5

6.0

IO=-20 µA I

=-20 µA

O

I

=-20 µA

O

I

=-4.0 mA

O

I

=-5.2 mA

O

IO=20 µA I

=20 µA

O

I

=20 µA

O

I

=4.0 mA

O

I

=5.2 mA

O

= VCC or GND

V

I

= VCC or GND

V

I

1.9 2.0 1.9 1.9

4.4 4.5 4.4 4.4

5.9 6.0 5.9 5.9

4.18 4.31 4.13 4.10

5.68 5.8 5.63 5.60

0.0 0.1 0.1 0.1

0.17 0.26 0.33 0.40

0.18 0.26 0.33 0.40 ± 0.1 ± 1 ± 1 µA

44080µA

2 to 6 V

CC CC

-55 to 125 °C

0 to 1000 ns

0 to 500 ns 0 to 400 ns

-40 to 85°C -55 to 125°C

V V

Unit

V4.5 3.15 3.15 3.15

V4.5 1.35 1.35 1.35

V

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