SN74AS151D Equivalent & Substitute Parts

Part Overview

The SN74AS151D is a 1 x 8:1 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 SN74AS151D operates with a single supply voltage between 4.5V and 5.5V and is suitable for applications requiring high-speed data selection across eight input lines.

Substiute Parts

SN74AS151D

Texas InstrumentsIn Stock: 2579SN74AS151D Datasheet

Current PartRFQ

SN74ALS151D

Texas InstrumentsIn Stock: 1407SN74ALS151D Datasheet

Parametric EquivalentRFQ

SN74ALS251D

Texas InstrumentsIn Stock: 1640SN74ALS251D Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the SN74AS151D is determined by strict equivalence across the following parameters:

• Circuit Configuration: 1 x 8:1 multiplexer topology
• Package Type: 16-SOIC surface mount package with identical physical dimensions (0.154", 3.90mm Width)
• Electrical Specifications: Voltage supply range 4.5V ~ 5.5V, output current ratings 2.6mA (high) and 24mA (low)
• Operating Temperature Range: 0°C ~ 70°C
• Compliance Standards: ROHS3 compliant, REACH unaffected, MSL 1

The substitute parts identified—SN74ALS151D and SN74ALS251D—maintain identical electrical performance and package specifications. The primary difference lies in the logic family designation (74ALS versus 74AS), which represents a different manufacturing series within Texas Instruments' standard logic portfolio. Both substitutes are functionally compatible for applications requiring 1 x 8:1 multiplexing in the specified voltage and temperature ranges.

Parameter Comparison

Engineering Selection Recommendations

The SN74AS151D is classified as obsolete, necessitating transition to available alternatives. Both SN74ALS151D and SN74ALS251D are designated as Last Time Buy, indicating limited future availability. Selection between these substitutes should prioritize current inventory status and procurement timelines.

All three parts maintain ROHS3 compliance and REACH unaffected status, ensuring regulatory alignment for new designs and legacy system support. The identical electrical specifications and 16-SOIC package footprint enable direct substitution without circuit redesign or PCB layout modification.

For applications requiring long-term component availability, evaluation of alternative multiplexer architectures from current production lines may be warranted beyond the scope of direct substitution.

Frequently Asked Questions (FAQ)

Q: Can SN74ALS151D and SN74ALS251D be used interchangeably with SN74AS151D?

A: Yes. Both parts maintain identical circuit configuration (1 x 8:1), package type (16-SOIC), electrical specifications (voltage supply, output current, operating temperature), and compliance certifications. Direct substitution is supported without circuit modification.

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

A: The 74AS and 74ALS designations represent different manufacturing series within Texas Instruments' standard logic portfolio. For the specified multiplexer function, both families deliver equivalent electrical performance and pin compatibility in the 16-SOIC package.

Q: Are there any package or footprint differences between these parts?

A: No. All three parts use the 16-SOIC package with identical physical dimensions (0.154", 3.90mm width). PCB layouts and assembly processes require no modification for substitution.

Q: What is the significance of the Last Time Buy status for SN74ALS151D and SN74ALS251D?

A: Last Time Buy status indicates that these parts are in the final phase of production availability. Procurement should account for limited future stock. The SN74AS151D is already classified as obsolete, making these substitutes the primary available options.

Q: Do all three parts meet the same compliance and environmental standards?

A: Yes. SN74AS151D, SN74ALS151D, and SN74ALS251D are all ROHS3 compliant, REACH unaffected, and carry MSL 1 (Unlimited) moisture sensitivity rating. Environmental and regulatory requirements are equivalent across all three parts.