54LS240FMQB

Overview

The 54LS240FMQB is a military-grade octal bus driver belonging to the LS TTL logic family. It features two independent four-bit buffers with inverted outputs and three-state control. The device utilizes a ceramic dual in-line package (CDIP) with 20 pins, designed for high-reliability applications. It operates within an extended temperature range of -55 °C to 125 °C, ensuring stable performance in harsh environments typical of aerospace and defense systems.

Feature Summary

• Octal configuration providing eight buffered output channels
• Three-state output capability for efficient bus line management
• Inverted logic polarity for signal inversion applications
• Military-grade construction using hermetic ceramic packaging

Applications

• Aerospace and defense electronic systems
• High-reliability computing bus architectures
• Harsh environment data transmission interfaces
• Military communication equipment signal routing

Procurement Notes

Verify the specific manufacturer source, as Rochester Electronics often handles legacy National Semiconductor inventory. Confirm the CDIP-20 ceramic package integrity and military grade rating. Ensure the part number suffix matches the required lead frame and seal specifications for your environmental constraints.

Selection Notes

Select this component when inverted octal buffering with three-state isolation is required in extreme temperature conditions. Compare against non-inverted variants like the 54LS244 if signal phase preservation is needed. Ensure system voltage levels align with standard LS TTL requirements.

Part Context

This component is part of the broader 54LS series, which defines military-grade Low-power Schottky TTL logic. It shares functional similarities with other octal drivers but is distinguished by its specific inverted output configuration and robust ceramic packaging suitable for long-term reliability.

Replacement Considerations

Direct substitutes include the DM54LS240 or SN54LS240 from compatible manufacturers. Verify pin compatibility and electrical characteristics before swapping. Non-inverted alternatives such as the 54LS244 require circuit logic adjustments.