54LS155FMQB

Overview

The 54LS155FMQB is a military-grade dual 2-line to 4-line decoder/demultiplexer manufactured by National Semiconductor. It operates on a nominal 5V supply with a range of 4.5V to 5.5V. The device features two independent decoders, each providing four active-low outputs selected by two address inputs and an enable input. Built on LS TTL technology, it supports a maximum propagation delay of 27ns at nominal voltage and functions within a temperature range of -55°C to 125°C.

Feature Summary

• Dual independent decoding channels for simultaneous signal routing
• Active-low output generation for direct interface with logic circuits
• Military-rated construction ensuring reliability in extreme environments

Applications

• Address decoding in military computing systems
• Data demultiplexing in avionics control units
• Signal selection in defense communication equipment

Procurement Notes

Verify the specific FMQB suffix against official National Semiconductor documentation to confirm package type and screening level. Ensure the component matches the required military qualification standards for your application. Cross-reference the manufacturer date code and lot number with authorized distributors to guarantee authenticity and traceability before procurement.

Selection Notes

Select this component when dual independent decoding is required in harsh environments. It is suitable for designs needing LS TTL compatibility with extended temperature ranges. Consider pinout compatibility if replacing older SN54LS155 variants. Verify power supply stability within the specified 4.5V to 5.5V range to ensure proper logic threshold operation.

Part Context

This part belongs to the 54LS series of high-speed low-power Schottky TTL logic devices. The 54-series designation indicates military-grade performance and wider operating temperatures compared to commercial 74-series equivalents. National Semiconductor, now part of Texas Instruments, produced these components for demanding industrial and defense applications requiring robust digital logic functionality.

Replacement Considerations

SN54LS155A is a documented equivalent from Texas Instruments offering identical logical function and pinout compatibility.