DM74LS156M Equivalent & Substitute Parts

Part Overview

The DM74LS156M is a Decoder/Demultiplexer logic integrated circuit with a 2 x 1:4 configuration, manufactured by onsemi in a 16-SOIC surface mount 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 and is suitable for applications requiring demultiplexing or decoding functions in digital logic circuits.

Substiute Parts

DM74LS156M

onsemiIn Stock: 852DM74LS156M Datasheet

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SN74LS156D

onsemiIn Stock: 1843SN74LS156D Datasheet

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SN74LS156DR

Texas InstrumentsIn Stock: 4097SN74LS156DR Datasheet

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SN74LS156NSR

Texas InstrumentsIn Stock: 2823SN74LS156NSR Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution for the DM74LS156M is determined by the following critical parameters:

• Circuit Configuration: All substitute parts must maintain the 2 x 1:4 decoder/demultiplexer topology
• Voltage Supply Range: All parts operate within 4.75V ~ 5.25V single supply specification
• Operating Temperature Range: All parts support 0°C ~ 70°C operating range
• Package Type: Substitutes must be 16-SOIC surface mount packages with compatible pinouts
• Output Current Specifications: Output current ratings (High and Low) determine functional equivalence

The substitute parts identified—SN74LS156NSR, SN74LS156D, and SN74LS156DR—share the same base product number (74LS156) and maintain electrical compatibility within the specified parameters. Variations in output current ratings and product status are noted for selection purposes.

Parameter Comparison

Engineering Selection Recommendations

SN74LS156DR (Texas Instruments) is the primary substitute for new designs and production. This part is active in product status, ROHS3 compliant, and maintains full electrical compatibility with the DM74LS156M across all critical parameters. The 16-SOIC package dimensions are identical to the original part.

SN74LS156NSR (Texas Instruments) provides an alternative with active product status and ROHS3 compliance. The package width differs (5.30mm vs. 3.90mm), requiring PCB layout verification before implementation.

SN74LS156D (onsemi) maintains onsemi manufacturer continuity but carries obsolete product status and non-compliant RoHS classification. This part is suitable only for legacy system maintenance where original manufacturer sourcing is required.

Output current specifications differ between the main part (400µA high) and all substitutes (100µA high). Applications requiring the higher output current of the DM74LS156M must be evaluated for functional compatibility with the reduced 100µA specification.

Frequently Asked Questions (FAQ)

Q: Can SN74LS156DR directly replace DM74LS156M in existing designs?

A: Yes, SN74LS156DR is electrically compatible across all critical parameters: circuit configuration, voltage supply range, operating temperature, and package type. The primary consideration is output current specification, where SN74LS156DR provides 100µA high output versus the original 400µA. Applications must be evaluated to confirm this reduction does not impact circuit performance.

Q: What is the difference between SN74LS156DR and SN74LS156NSR?

A: Both parts are manufactured by Texas Instruments with identical electrical specifications and active product status. The primary difference is package width: SN74LS156DR uses 16-SOIC (0.154", 3.90mm) matching the original DM74LS156M, while SN74LS156NSR uses 16-SOIC (0.209", 5.30mm). PCB layout compatibility must be confirmed before selecting SN74LS156NSR.

Q: Why is the DM74LS156M obsolete?

A: The DM74LS156M is classified as obsolete by the manufacturer. Active substitutes from Texas Instruments (SN74LS156DR and SN74LS156NSR) provide continued availability and support for this decoder/demultiplexer function.

Q: Are there compliance differences between substitute parts?

A: Yes. SN74LS156DR and SN74LS156NSR are both ROHS3 compliant with REACH unaffected status. SN74LS156D is RoHS non-compliant. For applications requiring RoHS compliance, SN74LS156DR or SN74LS156NSR must be selected.

Q: What packaging options are available?

A: All substitute parts use 16-SOIC surface mount packages. SN74LS156D and SN74LS156DR are available in standard 16-SOIC (0.154", 3.90mm width). SN74LS156NSR uses a wider 16-SOIC variant (0.209", 5.30mm width). Packaging format differs: SN74LS156D in Tube, SN74LS156DR in Tape & Reel, and SN74LS156NSR in Cut Tape & Digi-Reel.