SN74ALS251D

Overview

The SN74ALS251D is an Advanced Low-power Schottky (ALS) TTL integrated circuit functioning as an 8-line to 1-line multiplexer. It features complementary outputs and a 3-state capability, housed in a 16-pin SOIC package. The device operates within a supply voltage range of 4.5 V to 5.5 V, with a maximum propagation delay of 14 ns and a maximum power supply current of 19 mA. It supports a commercial operating temperature range from 0 °C to +70 °C.

Feature Summary

• Advanced Low-power Schottky technology provides high-speed switching with reduced power consumption compared to standard LS series devices.
• Integrated on-chip select logic decoding simplifies system design by eliminating external address decoding components.
• Complementary output configuration offers both assertion and negation signals for versatile logic interfacing.
• Three-state outputs allow direct connection to bus structures without additional isolation requirements.

Applications

• High-speed data routing in digital communication systems
• Universal function generation for complex logic circuits
• Parallel-to-serial data conversion modules

Procurement Notes

Verify the specific manufacturer datasheet for the SN74ALS251D to confirm pinout compatibility and electrical characteristics against your system requirements. Ensure the component meets the required ALS performance standards and packaging specifications before integration into production designs.

Selection Notes

Select this component when system design demands faster switching speeds than standard LS series parts while maintaining lower power dissipation than standard TTL. The 3-state outputs are essential for bus-oriented architectures requiring multiple drivers. Verify that the 4.5 V to 5.5 V supply range aligns with the target platform's voltage rails.

Part Context

This part belongs to the Texas Instruments SN74ALS family, which utilizes Advanced Low-power Schottky technology. This family bridges the performance gap between standard LS and Fast TTL families, offering improved speed and power efficiency. The SN74ALS251 specifically addresses applications requiring efficient 8-channel data selection with minimal power overhead.

Replacement Considerations

Compatible substitutes include the SN74F251 for higher speed or SN74LS251 for lower cost, provided timing and power constraints allow. Verify pin compatibility and electrical parameters such as propagation delay and output drive strength before substitution.