54F676LMQB

Overview

The 54F676LMQB is a 16-bit parallel-in serial-out shift register from the F/FAST series, manufactured by National Semiconductor. It features true outputs and operates in a right-counting direction. The device utilizes TTL logic levels and is housed in a 28-pin ceramic LCC package (CQCC28). It supports bidirectional data flow control and includes hold mode functionality with chip select capabilities that disable both serial and parallel operations when activated.

Feature Summary

• Parallel-to-serial conversion capability for 16-bit data words
• Hold mode with chip select to disable serial and parallel operations
• True output polarity configuration
• Right-direction counting sequence

Applications

• High-speed data serialization in communication systems
• Parallel data expansion in industrial control interfaces
• Shift register stages in military-grade digital signal processing chains

Procurement Notes

Verify the manufacturer origin carefully, as National Semiconductor assets were acquired by Texas Instruments. Confirm the specific lot traceability and MIL-STD-883 screening level if required for aerospace or defense applications. Ensure the ceramic package integrity matches the environmental specifications of the target deployment environment.

Selection Notes

Select this component when a robust 16-bit shift register with independent hold control is needed. The ceramic LCC package provides superior thermal stability compared to plastic variants. Consider the F/FAST speed grade for high-frequency timing requirements. Verify voltage compatibility with the system's 5V logic supply rails before integration.

Part Context

This part belongs to the legacy F/FAST logic family, known for high-speed performance in mixed-signal environments. The LMQB suffix typically denotes a military-grade qualification with specific screening standards. It serves as a critical interface component for converting parallel bus data into serial streams for transmission or storage in ruggedized electronic systems.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.