MM74HC138SJ Equivalent & Substitute Parts

Part Overview

The MM74HC138SJ is a Decoder/Demultiplexer logic IC with 1 x 3:8 circuit configuration in a 16-SOP package, manufactured by onsemi. This part is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement. The MM74HC138SJ operates as a single-supply decoder with output currents of 5.2mA (high and low), suitable for applications requiring address decoding and signal demultiplexing in digital logic circuits.

Substiute Parts

MM74HC138SJ

onsemiIn Stock: 944MM74HC138SJ Datasheet

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74HC138D,653

Nexperia USA Inc.In Stock: 8809774HC138D,653 Datasheet

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CD74HC138M

Harris CorporationIn Stock: 1262CD74HC138M Datasheet

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CD74HC138M96

Texas InstrumentsIn Stock: 2920CD74HC138M96 Datasheet

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CD74HC138MT

Texas InstrumentsIn Stock: 2564CD74HC138MT Datasheet

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CD74HC138QM96Q1

Texas InstrumentsIn Stock: 1910CD74HC138QM96Q1 Datasheet

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SN74HC138DG4

Texas InstrumentsIn Stock: 961SN74HC138DG4 Datasheet

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SN74HC138DR

Texas InstrumentsIn Stock: 30320SN74HC138DR Datasheet

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SN74HC138DT

Texas InstrumentsIn Stock: 2977SN74HC138DT Datasheet

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SN74HC138NSR

Texas InstrumentsIn Stock: 3316SN74HC138NSR Datasheet

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SN74HC138QDRG4Q1

Texas InstrumentsIn Stock: 3357SN74HC138QDRG4Q1 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the MM74HC138SJ is determined by strict equivalence in the following parameters:

• Circuit Configuration: 1 x 3:8 decoder/demultiplexer function
• Voltage Supply Range: 2V ~ 6V single supply operation
• Output Current Specifications: 5.2mA high and low output current
• Mounting Type: Surface mount technology
• Package Compatibility: 16-pin SOIC or 16-pin SO packages (physical dimensions must accommodate PCB layout)
• Functional Equivalence: All substitute parts must perform identical decoder/demultiplexer logic

Substitute parts are grouped by package type (16-SOIC with 0.154" width vs. 16-SO with 0.209" width) and product status (active vs. discontinued/obsolete). Temperature range variations and automotive qualifications are secondary differentiators that do not prevent functional substitution.

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation for Direct Replacement:

SN74HC138NSR (Texas Instruments) is the closest functional equivalent to MM74HC138SJ. Both parts share identical package dimensions (16-SOIC, 0.209" width), operating temperature range (-40°C ~ 85°C), and electrical specifications. SN74HC138NSR is currently active and ROHS3 compliant, providing long-term availability and regulatory compliance.

Alternative Recommendations by Application Requirements:

For designs requiring extended temperature operation (-55°C ~ 125°C), CD74HC138M96 or CD74HC138MT (Texas Instruments) provide superior thermal performance while maintaining all electrical equivalence. Both are ROHS3 compliant and active in inventory.

For automotive applications requiring AEC-Q100 qualification, CD74HC138QM96Q1 or SN74HC138QDRG4Q1 (Texas Instruments) are specified with automotive-grade certification and extended temperature ranges.

For general-purpose industrial applications with standard temperature requirements, SN74HC138DR (Texas Instruments) offers active product status, high inventory availability (30,300 pcs), and ROHS3 compliance.

Package Consideration:

The MM74HC138SJ uses a wider 16-SOIC package (0.209" width). Most substitute parts use the narrower 16-SOIC package (0.154" width). SN74HC138NSR maintains the original package width and is recommended for PCB layouts with tight spacing constraints. Narrower package alternatives require PCB layout verification before substitution.

Frequently Asked Questions (FAQ)

Q: Can I substitute MM74HC138SJ with any 74HC138 variant?

A: No. Substitution is limited to parts with identical circuit configuration (1 x 3:8), voltage supply range (2V ~ 6V), output current specifications (5.2mA high/low), and surface mount packaging. Package dimensions must be verified for PCB compatibility.

Q: What is the difference between 16-SOIC (0.209" width) and 16-SOIC (0.154" width)?

A: These are different physical package sizes. The 0.209" width package is wider and may not fit PCB footprints designed for the narrower 0.154" variant. Verify PCB layout compatibility before substitution. SN74HC138NSR maintains the original 0.209" width.

Q: Why are some substitute parts listed as "Discontinued at DiGi Electronics"?

A: These parts are no longer actively distributed through DiGi Electronics but may remain available through other suppliers or in existing inventory. For new designs, active status parts (SN74HC138DR, SN74HC138NSR, CD74HC138M96, SN74HC138QDRG4Q1) are recommended.

Q: Does operating temperature range affect substitution compatibility?

A: Operating temperature range does not prevent functional substitution if the application operates within the substitute part's specified range. Parts with extended temperature ranges (-55°C ~ 125°C) are compatible with applications requiring standard temperature operation (-40°C ~ 85°C), but not vice versa.

Q: What does ROHS3 compliance mean for this part?

A: ROHS3 compliance indicates the part meets Restriction of Hazardous Substances Directive requirements, restricting lead and other hazardous materials. For new designs and regulated applications, ROHS3 compliant substitutes are required. The original MM74HC138SJ does not specify RoHS status.

Q: Are automotive-qualified variants (AEC-Q100) required for my application?

A: Automotive qualification is required only for automotive applications. For industrial, consumer, or general-purpose applications, standard-grade parts (SN74HC138DR, CD74HC138M96) provide full functional equivalence at lower cost.