54ACQ244W-QML

Overview

The National Semiconductor 54ACQ244W-QML is a high-speed CMOS octal bus driver designed for aerospace and military applications. It features two independent 4-bit buffers with three-state outputs, controlled by active-low enable inputs (1G and 2G). The device operates on a single 5V supply within the AC series voltage range of 2V to 6V. It is housed in a hermetic ceramic package suitable for harsh environments, offering radiation hardness up to 300 krad (Si) total ionizing dose and immunity to single event latch-up.

Feature Summary

• Hermetic ceramic packaging ensures reliability in extreme environmental conditions
• High radiation hardness with immunity to single event latch-up and upset
• Three-state outputs facilitate direct connection to system buses
• Compatible with TTL logic levels for versatile interface capabilities

Applications

• Aerospace memory address drivers
• Military clock distribution systems
• Harsh environment bus-oriented receivers
• Radiation-hardened data acquisition interfaces

Procurement Notes

Verify QML-V qualification status and specific lot traceability requirements before procurement. Confirm that the hermetic seal integrity meets MIL-STD specifications for the intended operational altitude and pressure. Ensure the ordering documentation explicitly references the correct SMD drawing number to guarantee compliance with the required radiation hardness and temperature range standards.

Selection Notes

Select this component when radiation tolerance and long-term reliability in space or high-altitude environments are critical. The AC series offers higher speed than standard 54LS equivalents while maintaining low power consumption. Verify that the operating voltage range aligns with the system's 5V logic levels and that the hermetic package fits the available board real estate constraints.

Part Context

This part belongs to the 54AC/54ACT family of high-speed CMOS logic functions. These components are specifically engineered to meet stringent aerospace industry requirements. The family includes various gates, flip-flops, and bus interfaces, all characterized for radiation hardness and single-event effects, making them suitable for the most demanding electronic systems.

Replacement Considerations

Direct replacements include other QML-V qualified octal bus drivers from the same manufacturer or equivalent parts from Aeroflex such as the UT54ACS244 or UT54ACTS244. Ensure any substitute maintains the same hermetic ceramic package style and meets the identical radiation hardness specifications.