74F257ASJ Equivalent & Substitute Parts

Part Overview

The 74F257ASJ is a 4 x 2:1 multiplexer logic integrated circuit 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 74F257 series provides single-supply multiplexing functionality suitable for digital logic applications requiring channel selection and data routing.

Substiute Parts

74F257ASJ

onsemiIn Stock: 91974F257ASJ Datasheet

Current PartRFQ

SN74F257NSR

Texas InstrumentsIn Stock: 5078SN74F257NSR Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 74F257ASJ are qualified based on the following critical parameters that determine functional and mechanical compatibility:

• Circuit configuration: 4 x 2:1 multiplexer topology
• Output current specifications: 3mA high, 24mA low
• Single supply voltage range: 4.5V ~ 5.5V
• Operating temperature range: 0°C ~ 70°C
• Package type: 16-SOIC surface mount with 0.209" width (5.30mm)
• Base product number: 74F257 series

The SN74F257NSR from Texas Instruments meets all these electrical and mechanical requirements, providing direct substitution capability for the obsolete 74F257ASJ.

Parameter Comparison

Engineering Selection Recommendations

The SN74F257NSR is the qualified substitute for the 74F257ASJ. Both components share identical electrical specifications and mechanical packaging, ensuring pin-for-pin compatibility and functional equivalence. The primary distinction is product status: the 74F257ASJ is obsolete while the SN74F257NSR maintains active production status from Texas Instruments.

For new designs and production continuity, the SN74F257NSR is the appropriate selection. Both parts carry REACH Unaffected status and MSL Level 1 moisture sensitivity classification. The Texas Instruments device is available in Tape & Reel packaging format, supporting automated assembly processes.

Frequently Asked Questions (FAQ)

Q: Can the SN74F257NSR directly replace the 74F257ASJ in existing designs?

A: Yes. The SN74F257NSR provides pin-for-pin and functional equivalence. Electrical specifications, package dimensions, and operating parameters are identical across both components.

Q: What is the primary reason for substitution?

A: The 74F257ASJ is classified as obsolete. The SN74F257NSR maintains active production status, ensuring long-term availability and supply chain continuity.

Q: Are there packaging differences between these parts?

A: Both components use 16-SOIC surface mount packages with identical dimensions (0.209" width, 5.30mm). The SN74F257NSR is supplied in Tape & Reel format, while the 74F257ASJ uses standard SOP packaging. Both are compatible with standard PCB assembly equipment.

Q: Do these parts have different compliance certifications?

A: Both components share identical REACH and moisture sensitivity classifications. No compliance differences exist between the two parts.

Q: What are the key parameters that determine substitution eligibility?

A: Substitution is based on matching circuit configuration (4 x 2:1), output current ratings (3mA/24mA), supply voltage range (4.5V ~ 5.5V), operating temperature (0°C ~ 70°C), and package type (16-SOIC surface mount).