SN74AS258D Equivalent & Substitute Parts

Part Overview

The SN74AS258D is a 4 x 2:1 multiplexer logic integrated circuit manufactured by Texas Instruments in a 16-SOIC surface mount package. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement. The SN74AS258D operates with a single supply voltage between 4.5V and 5.5V and is suitable for applications requiring multiplexing functionality in the 0°C to 70°C operating temperature range.

Substiute Parts

SN74AS258D

Texas InstrumentsIn Stock: 2297SN74AS258D Datasheet

Current PartRFQ

SN74ALS257AD

Texas InstrumentsIn Stock: 1275SN74ALS257AD Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SN74AS258D is determined by strict equivalence across the following parameters:

• Circuit configuration: 4 x 2:1 multiplexer topology
• Package type: 16-SOIC surface mount form factor
• Voltage supply range: 4.5V ~ 5.5V single supply
• Output current specifications: 2.6mA (high), 24mA (low)
• Operating temperature range: 0°C ~ 70°C
• Independent circuits: 1

The SN74ALS257AD qualifies as a parametric equivalent based on identical electrical characteristics and mechanical compatibility. Both devices share the same functional circuit, package dimensions, voltage requirements, and output current ratings. The primary distinction lies in the logic family designation (74AS versus 74ALS), which reflects different manufacturing processes while maintaining electrical compatibility within the specified parameters.

Parameter Comparison

Engineering Selection Recommendations

The SN74ALS257AD is a direct parametric equivalent for the SN74AS258D. Both components meet identical electrical and mechanical specifications, ensuring functional compatibility in circuit applications. The SN74ALS257AD carries a Last Time Buy status, indicating limited availability but continued support from the manufacturer. Both parts maintain ROHS3 compliance and REACH unaffected status, satisfying regulatory requirements for current manufacturing environments.

Selection between these parts should be based on procurement availability and supply chain considerations. The SN74ALS257AD represents the recommended alternative given the obsolete status of the SN74AS258D.

Frequently Asked Questions (FAQ)

Q: Can the SN74ALS257AD directly replace the SN74AS258D in existing designs?

A: Yes. Both components share identical circuit configuration (4 x 2:1 multiplexer), package type (16-SOIC), voltage supply range (4.5V ~ 5.5V), output current ratings (2.6mA, 24mA), and operating temperature range (0°C ~ 70°C). No circuit modifications are required.

Q: What is the difference between the 74AS and 74ALS logic families?

A: The 74AS and 74ALS designations indicate different manufacturing process technologies. Both families maintain electrical compatibility within the specified parameters. The 74ALS family typically offers lower power consumption characteristics, though both parts meet the same functional and electrical requirements for this multiplexer application.

Q: Are there any compliance or regulatory differences between these parts?

A: No. Both the SN74AS258D and SN74ALS257AD are ROHS3 compliant and REACH unaffected, meeting current regulatory standards for electronic component manufacturing and use.

Q: What is the significance of the product status difference?

A: The SN74AS258D is classified as obsolete, meaning it is no longer in active production. The SN74ALS257AD carries a Last Time Buy status, indicating limited remaining availability before discontinuation. For new designs or ongoing procurement, the SN74ALS257AD should be prioritized.

Q: Are the package dimensions identical?

A: Yes. Both parts use the 16-SOIC package with dimensions of 0.154" width (3.90mm). PCB footprints and assembly processes are identical.