54FCT521
8-Bit Identity Comparator
General Description
The ’FCT521 is an expandable 8-bit comparator. It com-
pares two words of up to eight bits each and provides a LOW
output when the two words match bit for bit. The expansion
input I
A = B
also serves as an active LOW enable input.
Features
n Expandable to any word length
n Outputs sink capability of 32mA, source capability of 12
mA
n TTL input and output level compatible
n CMOS power consumption
n Standard microcircuit Drawing (SMD) 5962-8854301
Logic Symbols Connection Diagram
Pin Descriptions
Pin Names Description
A
0
–A
7
Word A Inputs
B
0
–B
7
Word B Inputs
T
A = B
Expansion or Enable Input
O
A = B
Identity Output
FACT™ is a trademark of Fairchild Semiconductor Corporation.
DS100968-1
IEEE/IEC
DS100968-4
Pin Assignment
for DIP and CERPACK
DS100968-2
Pin Assignment
for LCC
DS100968-3
September 1998
54FCT521
8-Bit
Identity
Comparator
© 1998 National Semiconductor Corporation DS100968 www.national.com