September 1998
54AC520 · 54ACT520 8-Bit Identity Comparator
General Description
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.
nExpandable to any word length
n20-pin package
nOutputs source/sink 24 mA
n'ACT520 has TTL-compatible inputs
nStandard Microcircuit Drawing (SMD) 54AC520: 5962-90916
54ACT520: 5962-89793
Features
n Compares two 8-bit words in 6.5 ns typ
Logic Symbols
IEEE/IEC
DS100234-1
DS100234-4
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Pin Names |
Description |
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A0±A7 |
Word A Inputs |
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B0±B7 |
Word B Inputs |
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TA = B |
Expansion or Enable Input |
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O |
A = B |
Identity Output |
FACT™ is a trademark of Fairchild Semiconductor Corporation.
Comparator Identity Bit-8 54ACT520 · 54AC520
© 1998 National Semiconductor Corporation |
DS100234 |
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Connection Diagrams
Pin Assignment |
Pin Assignment |
for DIP and Flatpak |
for LCC |
DS100234-3
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DS100234-2 |
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Truth Table |
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Inputs |
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Outputs |
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IA = B |
A, B |
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A = B |
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O |
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L |
A = B* |
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L |
L |
A ¹ B |
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H |
H |
A = B* |
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H |
H |
A ¹ B |
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H |
H = HIGH Voltage Level
L = LOW Voltage Level
*A0 = B0, A1 = B1, A2 = B2, etc.
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Logic Diagram
DS100234-5
Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays.
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