M54HC85
M74HC85
December 1992
4-BIT MAGNITUDE COMPARATOR
B1R
(Plastic Package)
ORDER CODES :
M54HC85F1R
M74HC85M1R
M74HC85B1R
M74HC85C1R
F1R
(Ceramic Package)
M1R
(Micro Package)
C1R
(Chip Carrier)
PIN CONNECTIONS (top view)
NC =
No Internal
Connection
INPUT AND OUTPUT EQUIVALENT CIRCUIT
DESCRIPTION
.
HIGH SPEED
t
PD
= 22 ns (TYP.) at V
CC
= 5 V
.
LOW POWER DISSIPATION
I
CC
= 4
A (MAX.) at T
A
= 25
C
.
HIGH NOISE IMMUNITY
V
NIH
= V
NIL
= 28 % V
CC
(MIN.)
.
OUTPUT DRIVE CAPABILITY
10 LSTTL LOADS
.
SYMMETRICAL OUTPUT IMPEDANCE
|I
OH
| = I
OL
= 4 mA (MIN.)
.
BALANCED PROPAGATION DELAYS
t
PLH
= t
PHL
.
WIDE OPERATING VOLTAGE RANGE
V
CC
(OPR) = 2 V to 6 V
.
PIN AND FUNCTION COMPATIBLE WITH
54/74LS85
The M54/74HC85 is a high speed CMOS 4-BIT
MAGNITUDE COMPARATOR fabricated in silicon
gate C
2
MOS technology. It has the same high
speed performance of LSTTL combined with true
CMOS low power consumption. This comparator
compares two 4-bit words and provides a high volt-
age level on one of the A > B out, A = B out and A < B
out outputs. The comparing bit number is easily ex-
panded by cascading several devices as shown in
the typical application. All inputs are equipped with
protection circuits against static discharge and tran-
sient excess voltage.
1/11
TRUTH TABLE
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
X: DON'T CARE
ABSOLUTE MAXIMUM RATINGS
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 Source Sink Current Per Output Pin
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
o
C
T
L
Lead Temperature (10 sec)
300
o
C
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition is not implied.
(*) 500 mW:
65
o
C derate to 300 mW by 10mW/
o
C: 65
o
C to 85
o
C
M54/M74HC85
3/11
AC ELECTRICAL CHARACTERISTICS (C
L
= 50 pF, Input t
r
= t
f
= 6 ns)
Symbol
Parameter
Test Conditions
Value
Unit
V
CC
(V)
T
A
= 25
o
C
54HC and 74HC
-40 to 85
o
C
74HC
-55 to 125
o
C
54HC
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
C
IN
Input Capacitance
5
10
10
10
pF
C
PD
(*)
Power Dissipation
Capacitance
23
pF
(*) 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 operting current can be obtained by the following equation. I
CC
(opr) = C
PD
V
CC
f
IN
+ I
CC
SWITCHING CHARACTERISTICS TEST
WAVEFORM
TEST CIRCUIT I
CC
(Opr.)
INPUT WAVEFORM IS THE SAME AS THAT IN CASE OF
SWITCHING CHARACTERISTICS TEST.
M54/M74HC85
5/11
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