Philips Semiconductors
Product specification
4-bit magnitude comparator
74HC/HCT85
Fig.4 Functional diagram.
APPLICATIONS
• Process controllers
• Servo-motor control
FUNCTION TABLE
COMPARING INPUTS
CASCADING INPUTS
OUTPUTS
A3, B3
A2, B2
A1, B1
A0, B0
IA>B
IA<B
IA=B
QA>B
QA<B
QA=B
A3>B3
A3<B3
A3=B3
A3=B3
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
H
L
H
L
L
H
L
L
L
L
L
A2>B2
A2<B2
H
A3=B3
A3=B3
A3=B3
A3=B3
A2=B2
A2=B2
A2=B2
A2=B2
A1>B1
A1<B1
A1=B1
A1=B1
X
X
X
X
X
X
X
X
X
X
X
X
X
X
H
L
H
L
L
H
L
L
L
L
L
A0>B0
A0<B0
H
A3=B3
A3=B3
A3=B3
A2=B2
A2=B2
A2=B2
A1=B1
A1=B1
A1=B1
A0=B0
A0=B0
A0=B0
H
L
L
L
H
L
L
L
H
H
L
L
L
H
L
L
L
H
A3=B3
A3=B3
A3=B3
A2=B2
A2=B2
A2=B2
A1=B1
A1=B1
A1=B1
A0=B0
A0=B0
A0=B0
X
H
L
X
H
L
H
L
L
L
L
H
L
L
H
H
L
L
Notes
1. H = HIGH voltage level
L = LOW voltage level
X = don’t care
December 1990
4
NXP [ NXP ]
