74ACT521SJ

Overview

The onsemi 74ACT521SJ is an 8-bit identity comparator integrated circuit manufactured using high-speed CMOS technology. It operates within a supply voltage range of 4.5V to 5.5V and features active low outputs that indicate equality between two 8-bit inputs. The device provides symmetrical output drive capabilities of 24mA for both high and low states, ensuring robust signal integrity. It exhibits a maximum propagation delay of 10ns at 5V with a 50pF load and maintains a quiescent current of 4µA. Packaged in a 20-SOIC surface-mount format, it supports industrial operating temperatures from -40°C to +85°C.

Feature Summary

• Provides magnitude comparison functionality with active low output assertion when input vectors are identical.
• Features high-speed CMOS architecture compatible with standard TTL logic input levels.
• Delivers strong symmetric output drive capability suitable for direct bus interfacing.

Applications

• Digital data path validation systems
• Address decoding circuits
• Data integrity verification modules

Procurement Notes

Verify the specific suffix designation against official manufacturer documentation to confirm package dimensions and tape/reel specifications. Confirm RoHS compliance status and environmental declarations directly from the datasheet. Ensure the ordering part number matches the required temperature grade and packaging format for your assembly process.

Selection Notes

Select this component for applications requiring precise 8-bit equality checking with fast response times. The ACT series offers improved speed over standard AC logic while maintaining compatibility with existing TTL interfaces. Consider the 20-SOIC package constraints and thermal dissipation requirements during PCB layout planning.

Part Context

This device belongs to the 74ACT family of logic components, designed to bridge the performance gap between older TTL standards and modern CMOS technologies. The 74ACT521 specifically addresses the need for parallel data comparison in digital systems, offering a compact solution for identity verification tasks without requiring external discrete components.

Replacement Considerations

Cross-reference with other manufacturers' 74ACT521 equivalents such as those from NXP or Texas Instruments. Verify pinout compatibility and electrical parameter alignment before substitution. Note that the 74ACT521SC variant shares similar functional characteristics but may differ in physical package width.