SN74ALS257ADR

Overview

The SN74ALS257ADR is a quad 2-to-1 data selector/multiplexer with 3-state outputs manufactured by Texas Instruments. It belongs to the ALS logic series and operates within a supply voltage range of 4.5 V to 5.5 V. The device features a propagation delay of 12 ns maximum from input A or B to output Y, and an address select delay of 18 ns maximum from A/B to output Y. It is housed in a 16-pin Small Outline (D) package and supports an operating temperature range of 0°C to 70°C.

Feature Summary

• Provides bus interface capability from multiple sources in high-performance systems
• Outputs 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

Applications

• Bus-organized systems requiring signal multiplexing
• High-performance systems needing multi-source bus interfaces
• Data selection circuits for 4-bit data paths

Procurement Notes

Verify the specific ordering suffix 'ADR' corresponds to the SOIC D package and tape-and-reel quantity of 2500 units. Confirm RoHS compliance status and lead finish details via the manufacturer's current packaging addendum. Ensure the component meets the required commercial temperature range specifications for the target application environment.

Selection Notes

Select this component for applications requiring quad 2-to-1 multiplexing with 3-state outputs in standard commercial environments. Compare against SN74AS257 variants if higher drive currents are necessary. Verify that the 16-pin SOIC footprint aligns with the PCB layout constraints and that the ALS logic family characteristics meet the system timing requirements.

Part Context

This part is part of the SN74ALS257A family, which includes ceramic DIP and LCCC options for military temperature ranges. The 'ADR' suffix specifically denotes the plastic small-outline package variant intended for surface-mount assembly. It shares functional compatibility with other devices in the ALS and AS logic families designed for similar data routing tasks.

Replacement Considerations

SN74ALS257AD is the tube version of the same device. SN74ALS257ANSR is the SOP NS package equivalent. SN74AS257D offers faster switching speeds but requires verification of electrical compatibility.