SN74AS138DR

Overview

The SN74AS138DR is a high-speed silicon-gate CMOS device from the Texas Instruments SN54AS/74AS logic family. It functions as a 3-line to 8-line decoder and demultiplexer housed in a 16-pin SOIC package. The component operates within a supply voltage range of 4.5 V to 5.5 V and supports a commercial operating temperature range of 0°C to +70°C. Key electrical characteristics include a propagation delay of 12 ns, low-level output current capability of 20 mA, and high-level output current of -2 mA.

Feature Summary

• Features Schottky-clamped inputs for enhanced performance and noise immunity
• Provides active-low outputs with three dedicated enable inputs for flexible system control
• Utilizes high-speed silicon-gate CMOS technology for reduced power consumption

Applications

• Address decoding for memory arrays
• Demultiplexing data streams in digital communication systems
• Control signal generation in industrial automation equipment

Procurement Notes

Verify that the ordering suffix 'D' corresponds to the standard 16-SOIC package configuration. Confirm RoHS compliance status through official manufacturer documentation or authorized distributor channels prior to procurement. Ensure the specific revision level matches design requirements.

Selection Notes

Select this component when high switching speed is required alongside moderate drive capabilities. The AS series offers superior performance compared to standard LS logic while maintaining lower power dissipation than older bipolar technologies. Verify input voltage levels align with the 4.5 V to 5.5 V supply specification.

Part Context

This part belongs to the SN54AS/74AS logic family, which represents a high-speed variant of the standard 7400-series logic. The AS designation indicates Advanced Schottky technology, providing faster propagation delays than ALS counterparts. The 138 function code specifically denotes a 3-to-8 line decoder architecture.

Replacement Considerations

SN74AS138DG4: Pin-compatible alternative with identical electrical specifications and package dimensions.