SN74LS399D

Overview

The SN74LS399D is a quad 2-input multiplexer manufactured by Texas Instruments, belonging to the LS-TTL logic family. It operates on a nominal 5 V supply with a range of 4.75 V to 5.25 V and features a maximum static current of 13 mA. The device provides four independent multiplexing channels within a 16-pin plastic Small Outline Package (SOP). Key electrical characteristics include a propagation delay of 32 ns at nominal supply voltage and a maximum low-level output current of 8 mA. It supports an operating temperature range from 0 °C to 70 °C.

Feature Summary

• Integrates four independent 2-input multiplexers into a single integrated circuit for efficient signal routing.
• Utilizes Low-power Schottky TTL technology to achieve high switching speeds while maintaining reduced power consumption.
• Features a compact 16-pin surface-mount SOP package designed for automated assembly and space-constrained layouts.

Applications

• Data selection in digital communication systems
• Signal routing in microprocessor-based control units
• Address decoding in memory subsystems

Procurement Notes

Verify that the specific order suffix matches the required packaging format, as standard designations may default to tube or tape-and-reel configurations depending on the manufacturer's current production allocation. Confirm RoHS compliance status explicitly, as older LS-TTL variants often carry non-compliant markings. Ensure the supplier source is authorized to guarantee authenticity and traceability for critical logic components.

Selection Notes

Select this component when designing circuits requiring multiple independent data paths controlled by common select lines. The LS-TTL series offers a balance of speed and power suitable for general-purpose logic applications. Verify that the system voltage remains strictly within the 4.75 V to 5.25 V window to ensure reliable operation and prevent damage to the internal transistor structures.

Part Context

This part belongs to the extensive SN74LSxx series of logic integrated circuits produced by Texas Instruments. The SN74LS399D specifically addresses the need for multi-channel data selection within standard TTL-compatible environments. It serves as a functional alternative to discrete multiplexer solutions, reducing board complexity and component count in legacy and industrial electronic designs.

Replacement Considerations

Direct pin-to-pin replacements include other SN74LS399 variants such as the SN74LS399N (PDIP) or SN74LS399DR (SOIC tape-and-reel). Cross-family substitutions require careful evaluation of voltage levels and drive capabilities.