74F521SJX

Overview

The Fairchild Semiconductor 74F521SJX is an expandable 8-bit magnitude comparator housed in a 20-pin SOIC package. It compares two 8-bit binary words and provides a LOW output when the inputs match bit-for-bit. The device operates with a synchronous design, featuring load/preset inputs for data handling. It supports bidirectional counting modes within its logic family context and includes TCO output characteristics typical of the F/FAST series.

Feature Summary

• Expandable architecture allows cascading for wider comparison tasks
• Provides active-low output signal upon exact bit-matching of input words
• Supports synchronous operation with dedicated load and preset control inputs

Applications

• Digital magnitude comparison circuits
• Address decoding systems
• Data validation logic

Procurement Notes

Verify the specific suffix SJX confirms the 20-lead Small Outline Integrated Circuit (SOIC) package configuration. Ensure compatibility with standard 5V logic levels associated with the 74F series. Confirm RoHS compliance status if required by assembly specifications. Cross-reference pinouts with official datasheets to prevent interface mismatches during PCB integration.

Selection Notes

Select this component for applications requiring precise 8-bit equality checking. Consider the F/FAST series speed characteristics for timing-sensitive designs. Evaluate power consumption relative to other logic families if efficiency is critical. Ensure the SOIC package fits the available board space and manufacturing capabilities.

Part Context

This part belongs to the 74F logic family, known for high-speed performance. The 74F521 specifically functions as an 8-bit comparator. It is distinct from counter or buffer devices in the same catalog. The SJX suffix denotes the surface-mount packaging variant.

Replacement Considerations

Check for direct equivalents from other manufacturers offering the 74F521 in SOIC-20 packages. Verify pin-to-pin compatibility before substitution. Ensure electrical parameters such as propagation delay and supply voltage ranges match the original design requirements.