74AC138CW Equivalent & Substitute Parts

Part Overview

The 74AC138CW is a Logic Integrated Circuit (IC) decoder/demultiplexer manufactured by onsemi. This component is classified as Obsolete, making it necessary to identify functionally equivalent substitute parts for ongoing design requirements and procurement needs. The 74AC138 base product series provides 1 x 3:8 decoder/demultiplexer functionality in standard logic configurations.

Substiute Parts

74AC138CW

onsemiIn Stock: 81674AC138CW Datasheet

Current PartRFQ

74AC138SC

Fairchild SemiconductorIn Stock: 221274AC138SC Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the 74AC138CW is based on the following critical parameters:

• Base product number alignment (74AC138)
• Functional equivalence as a decoder/demultiplexer with 1 x 3:8 circuit configuration
• Logic series compatibility (AC series)
• Electrical specifications: Single supply voltage operation (2V ~ 6V range), output current capability (24mA high/low), and operating temperature range (-40°C ~ 85°C)
• Surface mount packaging in 16-SOIC form factor

The substitute part 74AC138SC meets these criteria as an active product from Fairchild Semiconductor within the same 74AC logic series.

Parameter Comparison

Engineering Selection Recommendations

The 74AC138SC is the identified substitute for the obsolete 74AC138CW based on functional equivalence within the 74AC decoder/demultiplexer product family. The substitute part is currently in Active product status, ensuring ongoing availability and supply chain continuity. Both parts share the same base product number (74AC138) and circuit configuration (1 x 3:8), confirming functional compatibility.

The 74AC138SC carries EAR99 export classification and maintains REACH compliance through standard regulatory pathways. Selection of the active substitute part eliminates obsolescence risk while maintaining electrical and mechanical compatibility with existing designs.

Frequently Asked Questions (FAQ)

Q: Why is the 74AC138CW considered obsolete? A: The 74AC138CW is classified as Obsolete by its manufacturer (onsemi). Substitute parts from active product lines should be evaluated for new designs and ongoing procurement.

Q: Is the 74AC138SC a direct replacement for the 74AC138CW? A: The 74AC138SC is functionally equivalent as a 1 x 3:8 decoder/demultiplexer within the 74AC logic series. Both parts operate on single supply voltage and share the same base product number. Verify package compatibility with your specific PCB layout requirements.

Q: What is the package type for these parts? A: The 74AC138SC is supplied in 16-SOIC surface mount packaging (0.154" width, 3.90mm). Confirm this package type matches your design specifications before implementation.

Q: Are there any compliance or regulatory differences between these parts? A: The 74AC138SC carries EAR99 export classification and maintains REACH compliance. The 74AC138CW is marked as REACH Unaffected. Both parts meet standard regulatory requirements for their respective product statuses.

Q: What voltage and current specifications apply to the substitute part? A: The 74AC138SC operates with single supply voltage from 2V to 6V, with output current capability of 24mA for both high and low states. Operating temperature range is -40°C to 85°C.