74FST3257D

Overview

The onsemi 74FST3257D is a high-speed CMOS multiplexer/demultiplexer belonging to the 74FST logic family. It integrates four independent 2-to-1 multiplexers within a single package, providing flexible signal routing capabilities for digital systems. The device operates with a single power supply and features three-state outputs, allowing direct interface with system buses without additional buffering. Designed for surface-mount applications, it utilizes a compact TSSOP package to minimize board space while maintaining reliable performance in standard industrial temperature ranges.

Feature Summary

• Integrates four independent 2:1 multiplexer circuits for versatile data selection
• Features three-state outputs compatible with bus-oriented architectures
• Supports single-supply operation for simplified power design

Applications

• Data acquisition systems requiring signal path selection
• Bus switching and data routing in embedded controllers
• Communication interfaces needing multiplexed line driving

Procurement Notes

Verify the specific suffix against official documentation, as variations may indicate different packaging or environmental ratings. Confirm current availability status, as this component series may be subject to discontinuation notices. Cross-reference the manufacturer's latest datasheet to ensure compatibility with existing PCB footprints and voltage levels before finalizing procurement plans.

Selection Notes

Select this component when designing systems that require multiple independent signal paths with minimal propagation delay. Ensure the operating voltage range aligns with the system's power rails. Consider the thermal characteristics of the TSSOP package if high ambient temperatures are expected. Verify that the input logic levels are compatible with the driving sources to prevent undefined states during operation.

Part Context

This part belongs to the 74FST (Fast Switching Technology) family, known for high-speed performance comparable to Schottky TTL but with CMOS power efficiency. The 74FST3257 variant specifically addresses applications needing multiple mux channels. It serves as a legacy alternative to newer low-voltage families, often retained in designs requiring robust 5V operation and established supply chains.

Replacement Considerations

Check for pin-compatible alternatives from other manufacturers such as NXP or Texas Instruments. Verify that substitute parts maintain the same 16-TSSOP footprint and electrical specifications. Review any obsolescence notices for the original part to plan for long-term supply stability.