74AC520, 74ACT520
8-Bit Identity Comparator
tm
Features
General Description
■ Compares two 8-bit words in 6.5ns typ.
The AC/ACT520 are expandable 8-bit comparators.
They compare two words of up to eight bits each and
provide a LOW output when the two words match bit for
bit. The expansion input IA = B also serves as an active
LOW enable input.
■ Expandable to any word length
■ 20-pin package
■ Outputs source/sink 24mA
■ ACT520 has TTL-compatible inputs
Ordering Information
Order
Number
74AC520SC
Package
Number
M20B
Package Description
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300” Wide Body
74ACT520SC
M20B
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300” Wide Body
74ACT520SJ
M20D
20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
74ACT520PC
N20A
20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300” Wide
Device also available in Tape and Reel. Specify by appending suffix letter “X” to the ordering number.
Connection Diagram
Pin Descriptions
Pin Names
Description
A0–A7
Word A Inputs
B0–B7
Word B Inputs
TA = B
Expansion or Enable Input
OA = B
Identity Output
Truth Table
Inputs
Outputs
A, B
IA = B
L
A=
A≠B
L
H
B(1)
A=
H
B(1)
A≠B
OA = B
L
H
H
H
H = HIGH Voltage Level
L = LOW Voltage Level
Note:
1. A0 = B0, A1 = B1, A2 = B2, etc.
FACT™ is a trademark of Fairchild Semiconductor Corporation.
©1989 Fairchild Semiconductor Corporation
74AC520, 74ACT520 Rev. 1.4
www.fairchildsemi.com
74AC520, 74ACT520 8-Bit Identity Comparator
March 2007