MM54C85 MM74C85 4-Bit Magnitude Comparator
September 1989
MM54C85 MM74C85 4-Bit Magnitude Comparator
General Description
The MM54C85 MM74C85 is a four-bit magnitude compara-
tor which will perform comparison of straight binary or BCD
codes The circuit consists of eight comparing inputs (A0
A1 A2 A3 B0 B1 B2 B3) three cascading inputs (A
l
B
A
k
B and A
e
B) and three outputs (A
l
B A
k
B and
A
e
B) This device compares two four-bit words (A and B)
and determines whether they are 鈥樷€榞reater than 鈥欌€?鈥樷€榣ess
than 鈥欌€?or 鈥樷€榚qual to鈥欌€?each other by a high level on the appro-
priate output For words greater than four-bits units can be
cascaded by connecting the outputs (A
l
B A
k
B and
A
e
B) of the least significant stage to the cascade inputs
(A
l
B A
k
B and A
e
B) of the next-significant stage In
addition the least significant stage must have a high level
voltage (V
IN(1)
) applied to the A
e
B input and low level
voltage (V
IN(0)
) applied to A
l
B and A
k
B inputs
Features
Y
Y
Y
Y
Y
Y
Y
Wide supply voltage range
Guaranteed noise margin
High noise immunity
Low power
TTL compatibility
Expandable to 鈥楴鈥?stages
Applicable to binary or BCD
Low power pinout 54L85 74L85
3 0V to 15V
1 0V
0 4 V
CC
(typ )
fan out of 2
driving 74L
Logic Diagram
TL F 5886 鈥?1
C
1995 National Semiconductor Corporation
TL F 5886
RRD-B30M105 Printed in U S A
1
2
3
4
