SGS Thomson Microelectronics M74HC85TTR, M74HC85RM13TR, M74HC85M1R, M74HC85B1R Datasheet

M74HC85

4-BIT MAGNITUDE COMPARATOR

■ HIGH SPEED :

t

= 20 ns (TYP.) at VCC = 6V

PD

■ 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 85

DESCRIPTION

The M74HC85 is an high speed CMOS 4-BIT
MAGNITUDE COMPARATOR fabricated with
silicon gate C

2

MOS technology.
This comparator compares two 4-bit words and
provides an high voltage level on on e of the A>B
out, A=B out and A<B out outputs. The comparing

TSSOPDIP SOP

ORDER CODES

PACKAGE TUBE T & R

DIP M74HC85B1R

SOP M74HC85M1R M74HC85RM13TR

TSSOP M74HC85TTR

bit number is easily expanded by cascading
several devices as shown in the typical
application.
All inputs are equipped with protection circuits
against static discharge and transient excess
voltage.

PIN CONNECTION AND IEC LOGIC SYMBOLS

1/10July 2001

M74HC85

INPUT AND OUTPUT EQUIVALENT CIRCUIT PIN DESCRIPTION

PIN No SYMBOL NAME AND FUNCTION

2
3
4
5
6
7

9, 11, 14, 1

10, 12, 13,

15

8 GND Ground (0V)

16 Vcc Positive Supply Voltage

TRUTH TABLE

IN
IN

IN
OUT
OUT
OUT
B

0

A

0

A<B
A=B
A>B

A>B
A=B
A<B

to B
to A

A<B Expansion Input
A=B Expansion Input
A>B Expansion Input
A>B Expansion Output
A=B Expansion Output
A<B Expansion Output
Word B Inputs

3

Word A Inputs

3

COMPARING INPUTS

CASCADING INPUTS OUTPUTS

A>B A<B A=B A>B A<B A=B

A3 > B3 X X X X X X H L L
A3 = B3 A2 > B2 X X X X X H L L
A3 = B3 A2 = B2 A1 > B1 X X X X H L L
A3 = B3 A2 = B2 A1 = B1 A0 > B0 X X X H L L

LLLHHL
XXHLLH

A3 = B3 A2 = B2 A1 = B1 A0 = B0

LHLLHL
HLLHLL
HHLLLL

A3 = B3 A2 = B2 A1 = B1 A0 < B0 X X X L H L
A3 = B3 A2 = B2 A1 > B1 X X X X L H L
A3 = B3 A2 < B2 X X X X X L H L
A3 < B3 X X X X X X L H L

X : Don’t Care

2/10

LOGIC DIAGRAM

M74HC85

This log i c diagram has not be used to est i m at e propagation delays

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Value Unit

V

V

V

I

I

OK

I

I

or I

CC

P

T

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

RECOMMENDED OPERATING CONDITIONS

Symbol Parameter Value Unit

V

V

V

T

t

r

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

2 to 6 V

CC
CC

-55 to 125 °C
0 to 1000 ns

0 to 500 ns
0 to 400 ns

V
V

3/10