SN74ALS258AD

Overview

The SN74ALS258AD is a quad 2-input multiplexer manufactured by Texas Instruments in the 74ALS logic family. It features four independent data selectors with three-state outputs, designed to multiplex signals from 4-bit data sources to 4-output data lines in bus-organized systems. The device operates on a single power supply ranging from 4.5V to 5.5V and supports an operating temperature range of 0°C to 70°C. Packaged in a 16-pin Small Outline (D) SOIC format, it provides high-performance signal routing capabilities.

Feature Summary

• Provides four independent 2-to-1 data selection channels for efficient signal routing
• Features three-state outputs that isolate data lines when the output-enable input is inactive
• Designed specifically for bus-organized systems requiring direct interface with system buses

Applications

• Multiplexing signals from multiple 4-bit data sources onto shared data lines
• Providing bus interfaces between multiple sources in high-performance computing systems
• Routing specific data channels within digital logic circuits

Procurement Notes

Verify component authenticity through authorized distributors or direct manufacturer channels. Confirm package integrity upon receipt, as the SOIC form factor requires careful handling during surface-mount assembly. Ensure storage conditions align with moisture sensitivity level requirements to prevent solderability issues before reflow processing.

Selection Notes

Select this component when designing systems requiring isolated data path management via three-state control. The ALS series offers a balance of speed and power consumption suitable for standard TTL-compatible environments. Verify that the required voltage levels match the specified input thresholds for reliable logic switching across the operational temperature range.

Part Context

This part belongs to the broader SN54ALS25xA and SN74A(L)S25x(A) logic guide series. While the SN54 variants support military temperature ranges, the SN74ALS258AD is rated for commercial use. It shares functional similarities with the SN74ALS257A but differs in output polarity characteristics relative to its select inputs.

Replacement Considerations

SN74ALS258AN

FAQ

How does the output-enable input affect the data lines?

When the output-enable (OE) input is at a high logic level, the three-state outputs enter a high-impedance state, effectively disconnecting them from the data lines to prevent loading.

What is the function of the A/B select input?

The A/B input determines which of the two data inputs (A or B) is routed to the corresponding output Y for each of the four multiplexer channels.