74AC399PC

Signal Switches, Multiplexers, Decoders Overview

The Fairchild Semiconductor 74AC399PC is a Quad 2-Port Register belonging to the AC series. It integrates four independent 2:1 multiplexers followed by edge-triggered D flip-flops. The device operates on a supply voltage of 2V to 6V with output drive currents of 24mA for both high and low states. It features true outputs and supports a maximum operating frequency of 130MHz at nominal supply. The component is housed in a 16-lead Plastic Dual-In-Line Package (PDIP) and functions within a temperature range of -55°C to 125°C.

Signal Switches, Multiplexers, Decoders Feature Summary

• Integrates four independent 2:1 multiplexers feeding into edge-triggered D flip-flops
• Provides true output polarity for registered data signals
• Supports wide supply voltage operation from 2V to 6V
• Delivers high current drive capability of 24mA per output

Signal Switches, Multiplexers, Decoders Applications

• Data routing and selection in digital systems
• Parallel-to-serial conversion circuits
• High-speed register storage applications
• Multiplexed input buffering

Signal Switches, Multiplexers, Decoders Procurement Notes

Verify the specific package variant, as the 74AC399 series includes ceramic LCC and plastic DIP options. Confirm RoHS compliance status, as some variants are marked non-compliant. Check product lifecycle status, as this specific part may be obsolete. Ensure the ordering suffix matches the required lead frame and sealing material specifications for your assembly process.

Signal Switches, Multiplexers, Decoders Selection Notes

Select this component when a quad multiplexer-register combination is required in a single package. The AC series offers higher speed than standard 74LS equivalents while maintaining CMOS power efficiency. Consider the 16-pin PDIP package for through-hole prototyping or legacy board designs. Verify that the 2V minimum supply voltage aligns with your system's logic levels.

Signal Switches, Multiplexers, Decoders Part Context

This component is part of the Fairchild 74AC logic family, designed for high-speed CMOS applications. It serves as a logical equivalent to older bipolar technologies but with lower power consumption. The 74AC399 specifically combines multiplexing and registration functions, reducing component count in complex digital signal processing paths compared to discrete implementations.

Signal Switches, Multiplexers, Decoders Replacement Considerations

Public confirmed substitutes include the 74ACT399 for TTL-compatible voltage levels. Other AC series quad registers may serve similar functions if multiplexing is not required. Verify pin compatibility and electrical characteristics before substitution.