SN74LS251DR

Overview

The SN74LS251DR is an 8-line to 1-line multiplexer from the Texas Instruments LS series, housed in a 16-pin SOIC package. It features complementary 3-state outputs and operates within a supply voltage range of 4.75 V to 5.25 V. The device exhibits a maximum propagation delay of 45 ns and draws a maximum supply current of 10 mA. It supports an operating temperature range from 0 °C to 70 °C.

Feature Summary

• Provides high-speed data selection from eight input sources to a single output using Low Power Schottky technology.
• Features on-chip select logic decoding for simplified address control without external components.
• Delivers both assertion and negation outputs with 3-state capability for bus-driven applications.

Applications

• Universal function generation for logic functions of four variables
• Data routing in digital communication systems
• Address decoding in memory architectures

Procurement Notes

Verify the specific datasheet revision and manufacturer documentation for the SN74LS251DR to ensure compliance with required electrical specifications and environmental standards. Confirm that the SOIC-16 package dimensions and pinout align with the target PCB footprint design before finalizing procurement decisions.

Selection Notes

Select this component when a standard TTL-compatible 8-to-1 multiplexer with 3-state outputs is required. It is suitable for designs needing complementary signal paths and moderate switching speeds within a 5 V logic environment. Ensure thermal management meets the 70 °C maximum junction temperature limit.

Part Context

This part belongs to the SN74LS251 family of 8-input multiplexers. It shares functional compatibility with other LS-series devices like the SN74LS251J but differs in packaging. The DR suffix indicates a surface-mount SOIC variant, distinct from through-hole DIP options.

Replacement Considerations

The SN74LS251D serves as a direct equivalent from Motorola/NXP. Verify pinout compatibility and electrical tolerances against the SN74LS251J ceramic DIP version if package changes are acceptable.