74F251ASC

Signal Switches, Multiplexers, Decoders Overview

The onsemi 74F251ASC is an obsolete high-speed 8-input digital multiplexer with 3-STATE outputs, manufactured by Fairchild Semiconductor and now part of the onsemi portfolio. It operates on a single power supply ranging from 4.5V to 5.5V. The device features inverting and non-inverting outputs, allowing for versatile logic implementation. It utilizes three select inputs (S0–S2) to choose one bit of data from eight sources. The component is housed in a 16-Lead Small Outline Integrated Circuit (SOIC) package.

Signal Switches, Multiplexers, Decoders Feature Summary

• Provides multifunctional capability as a universal function generator for any logic function of four variables
• Includes on-chip select logic decoding to manage input selection via three control lines
• Features both assertion and negation 3-STATE outputs for flexible bus expansion and system integration

Signal Switches, Multiplexers, Decoders Applications

• Universal function generation for logic circuits
• Data routing and signal selection systems
• Bus expansion configurations requiring multi-device output tying

Signal Switches, Multiplexers, Decoders Procurement Notes

Verify that the 74F251ASC is no longer in production and confirm availability through authorized distributors or surplus suppliers. Ensure replacement components match the original electrical specifications and pinout compatibility. Check RoHS compliance status if required for current manufacturing standards. Validate that the selected substitute maintains the same 3-STATE output functionality and voltage operating range.

Signal Switches, Multiplexers, Decoders Selection Notes

Select this component for applications requiring high-speed data multiplexing with tri-state output capabilities. Consider the 16-pin SOIC package for surface-mount assembly requirements. Evaluate the need for both inverting and non-inverting outputs to simplify circuit design. Confirm that the operating temperature range meets the environmental conditions of the target application.

Signal Switches, Multiplexers, Decoders Part Context

This device belongs to the 74F series of logic integrated circuits, known for high-speed performance. Originally produced by Fairchild Semiconductor, it is now managed under the onsemi brand. The 74F251A variant specifically offers enhanced speed characteristics compared to standard TTL logic families, making it suitable for demanding digital switching applications.

Signal Switches, Multiplexers, Decoders Replacement Considerations

Publicly confirmed parameter-equivalent substitutes include SN74F251BD and SN74F251BDR from Texas Instruments. These alternatives maintain functional compatibility with the original device specifications.

Signal Switches, Multiplexers, Decoders FAQ

What is the function of the Output Enable (OE) input?

The OE input is active LOW. When activated, it enables the logic function at the output. When HIGH, both outputs enter a high impedance state.

How many select inputs does the 74F251ASC have?

The device has three select inputs labeled S0, S1, and S2, which control the position of the internal switch to select one of the eight data inputs.