74AC138SJX

Overview

The Fairchild Semiconductor 74AC138SJX is a high-speed CMOS logic device belonging to the AC series. It functions as a 3-to-8 line decoder and demultiplexer, providing eight active-low outputs selected by three binary address inputs. The component utilizes a 16-pin Small Outline Package (SOP) for surface-mount applications. It operates within a supply voltage range of 2.0 V to 6.0 V and supports an industrial operating temperature range from -40°C to +85°C.

Feature Summary

• Provides one-of-eight decoding or demultiplexing functionality with active-low outputs
• Features three binary address inputs for precise channel selection
• Incorporates multiple enable inputs to control device operation states

Applications

• Address decoding in microprocessor-based systems
• Demultiplexing data streams in digital communication circuits
• Memory chip select generation in embedded designs

Procurement Notes

Verify the specific suffix 'SJX' against official Fairchild documentation to confirm package dimensions and tape-and-reel specifications. Ensure compatibility with existing PCB footprints and reflow soldering profiles. Confirm RoHS compliance status through current datasheets, as manufacturing sources may have changed over time.

Selection Notes

Select this component when requiring high-speed decoding with low power consumption compared to standard TTL logic. The AC series offers improved switching speeds while maintaining CMOS noise immunity. Verify that the 2V to 6V supply range aligns with the target system's voltage rails and that the SOP-16 package fits the available board space constraints.

Part Context

This part belongs to the widely adopted 74AC logic family, designed for general-purpose digital applications. It serves as a successor to older HC series devices, offering faster propagation delays. The 74AC138 variant specifically addresses needs for multi-channel selection in complex digital architectures requiring reliable signal routing.