74F251ASJX

Signal Switches, Multiplexers, Decoders Overview

The onsemi 74F251ASJX is an obsolete high-speed 8-input digital multiplexer from the 74F series. It features a single circuit with three select inputs and both assertion and negation outputs. The device operates on a single power supply ranging from 4.5V to 5.5V. It utilizes a 16-lead Small Outline Package (SOP) with a width of 5.3mm, conforming to EIAJ TYPE II standards. The component supports surface mount installation and functions within an ambient temperature range of 0°C to +70°C.

Signal Switches, Multiplexers, Decoders Feature Summary

• Provides multifunctional capability for selecting one bit of data from up to eight sources
• Includes on-chip select logic decoding for efficient control
• Features inverting and non-inverting 3-STATE outputs for bus expansion

Signal Switches, Multiplexers, Decoders Applications

• Universal function generator for logic functions of four variables
• Data selection from multiple sources
• Logic replacement applications

Signal Switches, Multiplexers, Decoders Procurement Notes

This part number is officially discontinued and no longer manufactured by onsemi or its predecessor Fairchild Semiconductor. Procurement must rely on secondary market distributors for remaining stock. Verify authenticity carefully as obsolete components are frequently counterfeited. Confirm package integrity and pin condition upon receipt. Cross-reference with parameter-equivalent alternatives from other manufacturers if new production units are required for long-term projects.

Signal Switches, Multiplexers, Decoders Selection Notes

Select this component only for legacy system maintenance where specific form factors are mandatory. Evaluate functional equivalents from current manufacturers for improved availability. Ensure design compatibility with the 74F series electrical characteristics. Consider redesigning for modern packages if long-term supply stability is a priority. Verify that the SOP package dimensions fit existing board layouts without modification.

Signal Switches, Multiplexers, Decoders Part Context

The 74F251A belongs to the Fast (74F) logic family, known for higher speed compared to standard TTL. This specific variant includes the 'X' suffix indicating tape and reel packaging availability in active versions, though this specific order code is now obsolete. The device was originally produced by Fairchild Semiconductor before the company's restructuring into onsemi.

Signal Switches, Multiplexers, Decoders Replacement Considerations

Parameter-equivalent substitutes include SN74F251BD and SN74F251BDR from Texas Instruments.