1/10
July 2001
s
HIGH SPEED :
t
PD
= 20 ns (TYP.) at V
CC
= 6V
s
LOW POWER DISSIPATION:
I
CC
=4
A(MAX.) at T
A
=25C
s
HIGH NOISE IMMUNITY:
V
NIH
= V
NIL
= 28 % V
CC
(MIN.)
s
SYMMETRICAL OUTPUT IMPEDANCE:
|I
OH
| = I
OL
= 4mA (MIN)
s
BALANCED PROPAGATION DELAYS:
t
PLH
t
PHL
s
WIDE OPERATING VOLTAGE RANGE:
V
CC
(OPR) = 2V to 6V
s
PIN AND FUNCTION COMPATIBLE WITH
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 one of the A>B
out, A=B out and A<B out outputs. The comparing
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.
M74HC85
4-BIT MAGNITUDE COMPARATOR
PIN CONNECTION AND IEC LOGIC SYMBOLS
ORDER CODES
PACKAGE
TUBE
T & R
DIP
M74HC85B1R
SOP
M74HC85M1R
M74HC85RM13TR
TSSOP
M74HC85TTR
TSSOP
DIP
SOP
M74HC85
2/10
INPUT AND OUTPUT EQUIVALENT CIRCUIT
PIN DESCRIPTION
TRUTH TABLE
X : Don't Care
PIN No
SYMBOL
NAME AND FUNCTION
2
IN
A<B
A<B Expansion Input
3
IN
A=B
A=B Expansion Input
4
IN
A>B
A>B Expansion Input
5
OUT
A>B
A>B Expansion Output
6
OUT
A=B
A=B Expansion Output
7
OUT
A<B
A<B Expansion Output
9, 11, 14, 1
B
0
to B
3
Word B Inputs
10, 12, 13,
15
A
0
to A
3
Word A Inputs
8
GND
Ground (0V)
16
Vcc
Positive Supply Voltage
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
A3 = B3
A2 = B2
A1 = B1
A0 = B0
L
L
L
H
H
L
X
X
H
L
L
H
L
H
L
L
H
L
H
L
L
H
L
L
H
H
L
L
L
L
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
M74HC85
3/10
LOGIC DIAGRAM
This logic diagram has not be used to estimate propagation delays
ABSOLUTE MAXIMUM RATINGS
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
C; derate to 300mW by 10mW/
C from 65
C to 85
C
RECOMMENDED OPERATING CONDITIONS
Symbol
Parameter
Value
Unit
V
CC
Supply Voltage
-0.5 to +7
V
V
I
DC Input Voltage
-0.5 to V
CC
+ 0.5
V
V
O
DC Output Voltage
-0.5 to V
CC
+ 0.5
V
I
IK
DC Input Diode Current
20
mA
I
OK
DC Output Diode Current
20
mA
I
O
DC Output Current
25
mA
I
CC
or I
GND
DC V
CC
or Ground Current
50
mA
P
D
Power Dissipation
500(*)
mW
T
stg
Storage Temperature
-65 to +150
C
T
L
Lead Temperature (10 sec)
300
C
Symbol
Parameter
Value
Unit
V
CC
Supply Voltage
2 to 6
V
V
I
Input Voltage
0 to V
CC
V
V
O
Output Voltage
0 to V
CC
V
T
op
Operating Temperature
-55 to 125
C
t
r
, t
f
Input Rise and Fall Time
V
CC
= 2.0V
0 to 1000
ns
V
CC
= 4.5V
0 to 500
ns
V
CC
= 6.0V
0 to 400
ns
M74HC85
4/10
DC SPECIFICATIONS
AC ELECTRICAL CHARACTERISTICS (C
L
= 50 pF, Input t
r
= t
f
= 6ns)
Symbol
Parameter
Test Condition
Value
Unit
V
CC
(V)
T
A
= 25C
-40 to 85C
-55 to 125C
Min.
Typ.
Max.
Min.
Max.
Min.
Max.
V
IH
High Level Input
Voltage
2.0
1.5
1.5
1.5
V
4.5
3.15
3.15
3.15
6.0
4.2
4.2
4.2
V
IL
Low Level Input
Voltage
2.0
0.5
0.5
0.5
V
4.5
1.35
1.35
1.35
6.0
1.8
1.8
1.8
V
OH
High Level Output
Voltage
2.0
I
O
=-20
A
1.9
2.0
1.9
1.9
V
4.5
I
O
=-20
A
4.4
4.5
4.4
4.4
6.0
I
O
=-20
A
5.9
6.0
5.9
5.9
4.5
I
O
=-4.0 mA
4.18
4.31
4.13
4.10
6.0
I
O
=-5.2 mA
5.68
5.8
5.63
5.60
V
OL
Low Level Output
Voltage
2.0
I
O
=20
A
0.0
0.1
0.1
0.1
V
4.5
I
O
=20
A
0.0
0.1
0.1
0.1
6.0
I
O
=20
A
0.0
0.1
0.1
0.1
4.5
I
O
=4.0 mA
0.17
0.26
0.33
0.40
6.0
I
O
=5.2 mA
0.18
0.26
0.33
0.40
I
I
Input Leakage
Current
6.0
V
I
= V
CC
or GND
0.1
1
1
A
I
CC
Quiescent Supply
Current
6.0
V
I
= V
CC
or GND
4
40
80
A
Symbol
Parameter
Test Condition
Value
Unit
V
CC
(V)
T
A
= 25C
-40 to 85C
-55 to 125C
Min.
Typ.
Max.
Min.
Max.
Min.
Max.
t
TLH
t
THL
Output Transition
Time
2.0
30
75
95
110
ns
4.5
8
15
19
22
6.0
7
13
16
19
t
PLH
t
PHL
Propagation Delay
Time (A, B-OUT)
2.0
96
185
230
280
ns
4.5
24
37
46
56
6.0
20
31
39
48
t
PLH
t
PHL
Propagation Delay
Time
(CASCADE-OUT)
2.0
48
95
120
145
ns
4.5
12
19
24
29
6.0
10
16
20
25
M74HC85
5/10
CAPACITIVE CHARACTERISTICS
1) C
PD
is defined as the value of the IC's internal equivalent capacitance which is calculated from the operating current consumption without
load. (Refer to Test Circuit). Average operating current can be obtained by the following equation. I
CC(opr)
= C
PD
x V
CC
x f
IN
+ I
CC
TEST CIRCUIT
C
L
= 50pF or equivalent (includes jig and probe capacitance)
R
T
= Z
OUT
of pulse generator (typically 50
)
Symbol
Parameter
Test Condition
Value
Unit
V
CC
(V)
T
A
= 25C
-40 to 85C
-55 to 125C
Min.
Typ.
Max.
Min.
Max.
Min.
Max.
C
IN
Input Capacitance
5.0
5
10
10
10
pF
C
PD
Power Dissipation
Capacitance (note
1)
5.0
23
pF
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