DM74ALS138M Equivalent & Substitute Parts

Part Overview

The DM74ALS138M is a Decoder/Demultiplexer logic IC manufactured by onsemi, featuring a 1 x 3:8 circuit configuration in a 16-SOIC package. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and production continuity. The part operates on single supply voltage (4.5V ~ 5.5V) and is suitable for surface mount applications requiring decoder/demultiplexer functionality.

Substiute Parts

DM74ALS138M

onsemiIn Stock: 1320DM74ALS138M Datasheet

Current PartRFQ

SN74ALS138AD

Texas InstrumentsIn Stock: 2021SN74ALS138AD Datasheet

DirectRFQ

SN74ALS138ADR

Texas InstrumentsIn Stock: 1934SN74ALS138ADR Datasheet

DirectRFQ

SN74ALS138ANSR

Texas InstrumentsIn Stock: 3463SN74ALS138ANSR Datasheet

SimilarRFQ

SN74ALS137AD

Texas InstrumentsIn Stock: 783SN74ALS137AD Datasheet

Parametric EquivalentRFQ

SN74AS138D

Texas InstrumentsIn Stock: 1175SN74AS138D Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the DM74ALS138M are classified based on electrical and mechanical compatibility within the following parameters:

Direct Substitutes maintain identical electrical specifications and package dimensions (16-SOIC, 0.154" width), allowing pin-for-pin replacement:

• Voltage supply range: 4.5V ~ 5.5V
• Output current characteristics: 400µA, 8mA
• Circuit configuration: 1 x 3:8
• Operating temperature: 0°C ~ 70°C

Similar Substitutes share electrical specifications but differ in package width (16-SOIC, 0.209" width), requiring PCB layout verification:

• Identical electrical performance and circuit configuration
• Different physical footprint dimensions

Parametric Equivalents maintain electrical specifications and package dimensions but differ in base product series (74ALS137, 74AS138), requiring functional verification:

• Equivalent voltage supply and output current ratings
• Identical circuit configuration and package form factor
• Different logic series designation

Parameter Comparison

Engineering Selection Recommendations

Primary Selection (Direct Replacement): SN74ALS138ADR is the recommended primary substitute. This part maintains identical electrical specifications and package dimensions to the DM74ALS138M, carries Active product status ensuring long-term availability, and is ROHS3 compliant. The Cut Tape & Digi-Reel packaging format supports both prototype and production volumes.

Secondary Selection (Identical Footprint, Last Time Buy Status): SN74ALS138AD provides direct pin-for-pin compatibility with matching package dimensions. This part is suitable for applications where Last Time Buy status is acceptable for design cycles with defined end-of-life planning.

Alternative Selection (Package Width Variation): SN74ALS138ANSR maintains electrical equivalence but features a wider 16-SOIC package (0.209" vs. 0.154"). This part is Active status and suitable only if PCB layout accommodates the increased package width. Tape & Reel packaging supports high-volume production.

Parametric Equivalent Selection (Series Variation): SN74ALS137AD and SN74AS138D are parametric equivalents with identical electrical performance and matching package dimensions. These parts differ in base product series designation and require functional verification against specific circuit requirements before implementation.

Frequently Asked Questions (FAQ)

Q: Can SN74ALS138ADR directly replace DM74ALS138M without PCB modifications? A: Yes. SN74ALS138ADR is a direct substitute with identical pin configuration, package dimensions (16-SOIC, 0.154" width), voltage supply range, and output current specifications. No PCB layout changes are required.

Q: What is the difference between SN74ALS138AD and SN74ALS138ADR? A: Both parts are electrically identical with matching package dimensions. The primary difference is packaging format: SN74ALS138AD is supplied in Tube packaging, while SN74ALS138ADR is supplied in Cut Tape & Digi-Reel format. Product status differs (Last Time Buy vs. Active).

Q: Can SN74ALS138ANSR be used as a substitute? A: SN74ALS138ANSR is electrically equivalent but features a wider package body (0.209" vs. 0.154" width). Substitution requires verification that the PCB footprint and layout accommodate the increased package width. Electrical performance is identical.

Q: What is the difference between 74ALS and 74AS series parts? A: Both series maintain identical electrical specifications for this decoder/demultiplexer function, including voltage supply (4.5V ~ 5.5V) and output current ratings (400µA, 8mA). The series designation reflects different logic family characteristics. Functional verification is required before substitution.

Q: Why is DM74ALS138M listed as obsolete? A: Obsolete status indicates the part is no longer manufactured by onsemi. Active alternatives from Texas Instruments (SN74ALS138ADR, SN74ALS138ANSR, SN74AS138D) provide equivalent functionality with ongoing production support.

Q: Are all substitute parts RoHS compliant? A: All Texas Instruments substitute parts listed are ROHS3 compliant. The original DM74ALS138M carries REACH Unaffected status. Compliance requirements should be verified against specific application and regional regulations.