SN74LS138DRG4

Overview

The SN74LS138DRG4 is a high-speed CMOS 3-to-8 line decoder/demultiplexer manufactured by Texas Instruments. It operates within a supply voltage range of 2 V to 6 V and features a propagation delay of 45 ns. The device supports surface-mount installation in an SOIC-16 package and functions reliably across an operating temperature range from -40 °C to +85 °C.

Feature Summary

• Provides decoding and demultiplexing functionality for three input lines to eight output lines
• Utilizes high-speed CMOS technology for efficient power consumption and performance
• Includes active-low outputs suitable for direct interfacing with various logic families

Applications

• Address decoding for memory and I/O mapping in embedded systems
• Demultiplexing data streams in digital communication circuits
• Control signal generation for peripheral device selection

Procurement Notes

Verify the specific suffix 'RG4' against current manufacturer documentation, as it may indicate RoHS compliance or specific tape-and-reel packaging variations. Confirm availability status, as this component has been identified as obsolete or discontinued in some distributor records. Ensure that any substitute components maintain compatible pinouts and electrical characteristics to guarantee circuit integrity during procurement.

Selection Notes

Select this component when a standard 3-to-8 decoder is required with low power consumption typical of CMOS technology. It is suitable for designs needing operation over a wide voltage range and extended industrial temperature limits. Consider alternative series if higher drive currents or faster switching speeds are necessary, as LS-family equivalents may offer different electrical profiles.

Part Context

This part belongs to the SN74HC138 family, representing a CMOS implementation of the classic 74138 decoder function. It serves as a modern replacement for older bipolar LS-series devices, offering improved noise immunity and lower static power dissipation while maintaining functional compatibility with standard TTL logic levels in many applications.

Replacement Considerations

The SN74HC138DRE4 is a documented equivalent within the same product family. Verify pin compatibility and electrical specifications before substitution.