MM74HC251SJ Equivalent & Substitute Parts

Part Overview

The MM74HC251SJ is a 1 x 8:1 multiplexer logic IC manufactured by onsemi in a 16-SOP surface mount package. This component is classified as obsolete, making equivalent substitute parts necessary for new designs and ongoing production requirements. The 74HC251 series provides single-supply multiplexing functionality across the 2V to 6V operating range with industrial temperature specifications.

Substiute Parts

MM74HC251SJ

onsemiIn Stock: 764MM74HC251SJ Datasheet

Current PartRFQ

SN74HC251NSR

Texas InstrumentsIn Stock: 2987SN74HC251NSR Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the MM74HC251SJ is determined by the following critical parameters:

• Circuit Configuration: Must be 1 x 8:1 multiplexer topology
• Package Compatibility: 16-SOIC (0.209", 5.30mm Width) surface mount package
• Voltage Supply Range: 2V ~ 6V single supply operation
• Operating Temperature Range: -40°C ~ 85°C industrial grade
• Base Product Series: 74HC251 logic family

The SN74HC251NSR from Texas Instruments meets all substitution criteria within these allowed parameters. Both parts share identical package geometry, voltage specifications, temperature range, and functional circuit configuration, enabling direct substitution in applications currently using the MM74HC251SJ.

Parameter Comparison

Engineering Selection Recommendations

The SN74HC251NSR is the primary substitute for the obsolete MM74HC251SJ. Selection is based on the following factors:

Product Status: The MM74HC251SJ is obsolete, while the SN74HC251NSR maintains active production status, ensuring long-term availability and supply chain continuity.

Compliance & Certifications: Both parts share identical REACH status (REACH Unaffected), ECCN classification (EAR99), and HTSUS codes (8542.39.0001), maintaining regulatory alignment across substitution.

Electrical Compatibility: Both parts operate within the 2V to 6V supply range and -40°C to 85°C temperature specification. The SN74HC251NSR exhibits higher output current capability (7.8mA vs. 5.2mA), which provides improved drive capability without compromising compatibility.

Package Equivalence: Identical 16-SOIC package geometry and surface mount configuration enable direct PCB layout compatibility without redesign.

Frequently Asked Questions (FAQ)

Q: Can the SN74HC251NSR directly replace the MM74HC251SJ on existing PCBs?

A: Yes. Both parts use the 16-SOIC package with identical pin configuration and spacing (0.209", 5.30mm width). No PCB layout modifications are required.

Q: Are there voltage supply differences between these parts?

A: No. Both the MM74HC251SJ and SN74HC251NSR operate across the same 2V to 6V single supply range and share identical operating temperature specifications of -40°C to 85°C.

Q: What is the significance of the higher output current in the SN74HC251NSR?

A: The SN74HC251NSR provides 7.8mA output current compared to 5.2mA in the MM74HC251SJ. This increased drive capability enhances signal integrity and fan-out capacity while maintaining full functional compatibility.

Q: Are there any compliance or regulatory differences?

A: No. Both parts share identical REACH status, ECCN classification, and HTSUS codes, ensuring equivalent regulatory compliance for export and supply chain documentation.

Q: Why is the MM74HC251SJ classified as obsolete?

A: Obsolete status indicates the manufacturer (onsemi) has discontinued production. The SN74HC251NSR from Texas Instruments provides equivalent functionality with active production support.

Q: What packaging options are available for the substitute?

A: The SN74HC251NSR is supplied in Tape & Reel (TR) packaging for automated assembly processes, while the original MM74HC251SJ was supplied in standard packaging. Both use the same 16-SOIC component form factor.