SN74ALS257AD

Overview

The SN74ALS257AD is a quad 2-input data selector/multiplexer manufactured by Texas Instruments in the AS logic series. It operates on a single power supply ranging from 4.5 V to 5.5 V and features four independent circuits within a 16-pin SOIC package. The device provides tri-state outputs that interface directly with system buses, ensuring minimal loading when disabled. Designed for commercial temperature ranges of 0°C to 70°C, it supports high-performance bus-organized systems by multiplexing signals from 4-bit data sources to 4-output data lines efficiently.

Feature Summary

• Provides tri-state outputs that do not load data lines when the output-enable input is at a high logic level
• Designed to multiplex signals from 4-bit data sources to 4-output data lines in bus-organized systems
• Interfaces directly with system buses to provide bus interface from multiple sources in high-performance systems

Applications

• Multiplexing signals from 4-bit data sources to 4-output data lines
• Providing bus interface from multiple sources in high-performance systems
• Direct interfacing with system buses

Procurement Notes

Verify the specific ordering suffix 'D' corresponds to the SOIC package variant. Confirm RoHS compliance status and lead finish details via the manufacturer's current packaging addendum. Ensure the component meets the required operating temperature range of 0°C to 70°C for your application environment before finalizing procurement specifications.

Selection Notes

Select this component for applications requiring quad 2-to-1 data selection with tri-state outputs in standard 5V logic environments. Consider the SN74AS257D for higher drive current capabilities or the SN74ALS257AN if a PDIP package is preferred. Verify that the 4.5V to 5.5V supply voltage aligns with your system design constraints and that the SOIC footprint fits your PCB layout requirements.

Part Context

This part belongs to the SN74ALS/AS257 family of data selectors and multiplexers. It shares functional similarities with the SN74ALS258A and SN74AS258, which differ primarily in output enable polarity. The device is part of Texas Instruments' broader 74-series logic portfolio, designed for compatibility with standard digital logic interfaces while offering enhanced performance characteristics suitable for complex bus architectures.

Replacement Considerations

SN74AS257D offers equivalent functionality with higher drive current specifications. SN74ALS257AN provides the same logical operation in a PDIP package format. SN74ALS258A serves as a pin-compatible alternative with inverted output enable logic.