DM74LS138M Equivalent & Substitute Parts

Part Overview

The DM74LS138M is a Decoder/Demultiplexer logic IC manufactured by onsemi in a 16-SOIC package configuration. This component implements a 1 x 3:8 decoder/demultiplexer function with single supply operation. The DM74LS138M carries an obsolete product status, making equivalent and substitute parts necessary for ongoing design support and procurement continuity. Substitute parts maintain identical functional specifications and electrical parameters while offering active product status from alternative manufacturers.

Substiute Parts

DM74LS138M

onsemiIn Stock: 1125DM74LS138M Datasheet

Current PartRFQ

SN74LS138DR

Texas InstrumentsIn Stock: 7656SN74LS138DR Datasheet

SimilarRFQ

SN74LS138NSR

Texas InstrumentsIn Stock: 2865SN74LS138NSR Datasheet

SimilarRFQ

SN74LS138D

Texas InstrumentsIn Stock: 2343SN74LS138D Datasheet

Parametric EquivalentRFQ

SN74S138AD

Texas InstrumentsIn Stock: 1055SN74S138AD Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the DM74LS138M is determined by strict equivalence across the following parameters: decoder/demultiplexer configuration (1 x 3:8), independent circuits count (1), output current specifications (400µA high, 8mA low), single supply voltage operation within 4.75V ~ 5.25V range, operating temperature range (0°C ~ 70°C), surface mount mounting type, and 16-SOIC package footprint. All substitute parts listed maintain these electrical and mechanical specifications without deviation. Series variations (74LS versus 74S) are included where parametric equivalence is confirmed. Packaging format differences (Cut Tape, Tape & Reel, Tube) do not affect functional substitution and reflect supplier distribution options only.

Parameter Comparison

Engineering Selection Recommendations

All listed substitute parts maintain full parametric equivalence to the DM74LS138M across electrical and mechanical specifications. Selection among substitute options should be based on product status and compliance requirements. Texas Instruments SN74LS138DR, SN74LS138NSR, and SN74LS138D all carry active product status with ROHS3 compliance certification, providing long-term availability assurance. The SN74S138AD offers active status and ROHS3 compliance with series-level equivalence (74S versus 74LS). Packaging format selection (Cut Tape, Tape & Reel, or Tube) depends on procurement volume and assembly process requirements; all formats are functionally equivalent. For applications requiring the narrowest package footprint (0.154" width), SN74LS138DR, SN74LS138D, and SN74S138AD are appropriate selections. The SN74LS138NSR features a wider 0.209" package footprint while maintaining identical electrical performance.

Frequently Asked Questions (FAQ)

Q: Can SN74LS138DR directly replace DM74LS138M in existing designs? A: Yes. The SN74LS138DR maintains identical electrical specifications (1 x 3:8 decoder/demultiplexer configuration, 400µA/8mA output currents, 4.75V ~ 5.25V supply, 0°C ~ 70°C operating range) and package footprint (16-SOIC, 0.154" width). No circuit modifications are required.

Q: What is the difference between SN74LS138NSR and SN74LS138DR? A: Both parts are functionally equivalent with identical electrical parameters. The primary difference is package width: SN74LS138NSR measures 0.209" (5.30mm) while SN74LS138DR measures 0.154" (3.90mm). Packaging format also differs (Tape & Reel versus Cut Tape & Digi-Reel). PCB footprint compatibility must be verified for the wider package variant.

Q: Is SN74S138AD compatible with designs specified for 74LS series? A: Yes. The SN74S138AD maintains identical electrical specifications and package footprint as the 74LS variants. The 74S series designation indicates faster switching characteristics within the same functional specification set. No design modifications are required for substitution.

Q: What compliance certifications apply to substitute parts? A: All Texas Instruments substitute parts (SN74LS138DR, SN74LS138NSR, SN74LS138D, SN74S138AD) carry ROHS3 compliance and REACH Unaffected status. These certifications ensure regulatory compliance for applications subject to environmental and hazardous substance restrictions.

Q: Are there inventory considerations when selecting among substitute parts? A: Yes. Current inventory levels vary: SN74LS138DR (7558 pcs), SN74LS138NSR (2790 pcs), SN74LS138D (2260 pcs), and SN74S138AD (956 pcs). Procurement timelines and volume requirements may influence part selection based on available stock.