74FCT377PC

Overview

The National Semiconductor 74FCT377PC is an octal D-type flip-flop featuring clock enable functionality. It operates within a supply voltage range of 4.5V to 5.5V and supports through-hole mounting in a 20-pin PLCC package. The device provides true outputs with high impedance states during power-up and power-down cycles, ensuring glitch-free bus loading. It includes latchup protection and is designed for positive edge-triggered operation with individual data inputs and corresponding Q outputs.

Feature Summary

• Octal D-type flip-flop architecture with dedicated clock enable control
• High impedance glitch-free bus loading throughout power transitions
• Guaranteed latchup protection for enhanced reliability
• Positive edge-triggered operation with true output polarity

Applications

• Parallel data storage in digital systems
• Bus interface circuits requiring tri-state outputs
• Clock distribution networks with enable gating
• Memory buffer applications in microprocessor systems

Procurement Notes

Verify component authenticity due to potential availability from multiple distributors after original manufacturer transitions. Confirm package integrity and pin alignment for the 20-pin PLCC form factor. Check RoHS compliance status as legacy parts may vary by production batch. Ensure storage conditions meet moisture sensitivity level requirements before reflow or insertion. Validate datasheet revisions against specific manufacturing date codes for accurate electrical characteristics.

Selection Notes

Select this component when octal storage with independent clock enable is required in through-hole designs. Compare propagation delay specifications against system timing constraints at 5V operation. Evaluate current drive capabilities relative to load requirements on parallel buses. Consider thermal performance within the specified operating temperature range. Verify compatibility with existing logic families and voltage levels in the target circuit design.

Part Context

This part belongs to the FCT (Fast CMOS Technology) series, bridging TTL speed with CMOS low power consumption. It serves as a standard octal register in legacy digital designs. The PLCC package offers compact surface-mount-like density with through-hole compatibility. National Semiconductor's FCT line was widely adopted for high-speed parallel interfaces before transitioning to newer technology nodes.

Replacement Considerations

Cross-reference with SN74FCT377PC or similar octal D-flip-flops with clock enable. Verify pinout compatibility and electrical parameters match original specifications. Check for equivalent latchup protection and output drive strength. Confirm package dimensions align with existing PCB footprints. Review manufacturer documentation for any functional differences in clock enable behavior.