74F251ASCX Equivalent & Substitute Parts

Part Overview

The 74F251ASCX is a 1 x 8:1 multiplexer logic integrated circuit manufactured by onsemi in a 16-SOIC surface mount package. This component is classified as obsolete, making equivalent substitute parts necessary for new designs and ongoing production requirements. The 74F251 series provides single-supply multiplexing functionality with standardized electrical characteristics suitable for digital logic applications requiring data selection from eight input lines.

Substiute Parts

74F251ASCX

onsemiIn Stock: 1014274F251ASCX Datasheet

Current PartRFQ

SN74F251BD

Texas InstrumentsIn Stock: 2026SN74F251BD Datasheet

DirectRFQ

SN74F251BDR

Texas InstrumentsIn Stock: 2999SN74F251BDR Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the 74F251ASCX is determined by strict equivalence across the following parameters:

• Multiplexer Configuration: 1 x 8:1 circuit topology
• Package Type: 16-SOIC surface mount package with 0.154" (3.90mm) width
• Electrical Specifications: Single supply voltage range 4.5V ~ 5.5V, output current ratings 3mA high and 24mA low
• Operating Temperature Range: 0°C ~ 70°C
• Series Compatibility: 74F logic family

All substitute parts listed maintain identical electrical and mechanical parameters, ensuring direct functional replacement without circuit redesign.

Parameter Comparison

Engineering Selection Recommendations

SN74F251BDR (Texas Instruments) is the primary substitute for new designs and production. This part carries Active product status, ensuring long-term availability and supply chain stability. It is ROHS3 compliant and supplied in Tape & Reel format, standard for automated assembly processes. All electrical and mechanical parameters are identical to the 74F251ASCX.

SN74F251BD (Texas Instruments) is available as a secondary option with Last Time Buy status, indicating limited future availability. This part is supplied in Tube packaging and maintains full electrical equivalence. Selection of this part should account for its discontinuation trajectory.

Both Texas Instruments substitutes carry REACH Unaffected and EAR99 export classification status, matching the original part's regulatory profile.

Frequently Asked Questions (FAQ)

Q: Can SN74F251BDR directly replace 74F251ASCX without circuit modification?

A: Yes. The SN74F251BDR maintains identical electrical specifications (voltage supply, output current, operating temperature) and package configuration (16-SOIC surface mount). No circuit redesign is required.

Q: What is the difference between SN74F251BD and SN74F251BDR?

A: Both parts are electrically identical. The primary difference is packaging format: SN74F251BD is supplied in Tube packaging, while SN74F251BDR is supplied in Tape & Reel format. Tape & Reel is standard for high-volume automated assembly. SN74F251BDR also maintains Active product status, while SN74F251BD is Last Time Buy.

Q: Why is the 74F251ASCX obsolete?

A: The 74F251ASCX is classified as obsolete by onsemi. Texas Instruments continues to manufacture equivalent 74F251 variants, making cross-manufacturer substitution the appropriate path for ongoing applications.

Q: Are there any compliance differences between the original and substitute parts?

A: No. All parts share identical REACH status (REACH Unaffected), ECCN classification (EAR99), and HTSUS codes (8542.39.0001). The substitute parts add ROHS3 compliance certification, which represents an enhancement rather than a deviation.

Q: What is MSL 1 (Unlimited) rating?

A: MSL 1 (Unlimited) indicates the component has unlimited shelf life and requires no special moisture control during storage or handling. All listed parts carry this rating.