74ACT521MTCX

Overview

The Fairchild Semiconductor 74ACT521MTCX is an expandable 8-bit magnitude comparator integrated circuit. It compares two 8-bit words and provides a low output when the inputs match bit-for-bit. The device operates on a supply voltage of 4.5V to 5.5V with a maximum frequency of 75MHz. It features active-low outputs and is housed in a 20-TSSOP package (MO-153AC). Key electrical parameters include a propagation delay of 10ns at 5V with 50pF load, quiescent current of 4µA, and output drive capability of 24mA.

Feature Summary

• Expandable architecture for cascading multiple units
• Active-low identity output indicating exact bit matching
• High-speed CMOS technology for efficient operation
• Wide operating temperature range support

Applications

• Digital data comparison circuits
• Address decoding systems
• Error detection logic modules
• Identity verification hardware

Procurement Notes

Verify manufacturer origin between Fairchild Semiconductor and onsemi due to corporate acquisition history. Confirm package marking matches MO-153AC TSSOP-20 specifications. Ensure RoHS compliance documentation aligns with current environmental standards. Check for moisture sensitivity level 1 handling requirements during storage and assembly processes.

Selection Notes

Select this component for applications requiring precise 8-bit equality checking with active-low signaling. Consider the 4.5V to 5.5V supply constraint for compatibility with standard logic families. Evaluate the 24mA output drive against load requirements. Verify pinout compatibility if replacing legacy components in existing designs.

Part Context

Part of the 74ACT series family, designed for high-speed digital applications. Shares functional similarities with 74ACT521SC but utilizes TSSOP packaging instead of SOIC. Offers comparable performance metrics within the AC/ACT logic family lineage.

Replacement Considerations

• 74ACT521SC

FAQ

What is the output state when inputs do not match?

The output remains high when the two 8-bit input words are not identical.

Is the device suitable for cascading?

Yes, it is an expandable comparator designed for cascading multiple units.