74AC251SC Equivalent & Substitute Parts

Part Overview

The 74AC251SC 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 74AC251 series provides single-supply multiplexing functionality suitable for digital logic applications requiring channel selection across eight input lines.

Substiute Parts

74AC251SC

onsemiIn Stock: 88674AC251SC Datasheet

Current PartRFQ

CD74AC251M

Texas InstrumentsIn Stock: 1978CD74AC251M Datasheet

SimilarRFQ

CD74AC251M96

Texas InstrumentsIn Stock: 5130CD74AC251M96 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the 74AC251SC is determined by strict adherence to the following electrical and mechanical parameters:

Critical Compatibility Parameters:

• Circuit configuration: 1 x 8:1 multiplexer topology
• Package type: 16-SOIC surface mount form factor
• Base product series: 74AC251
• Mounting compatibility: Surface mount technology

Acceptable Parameter Variations: Substitute parts may exceed the original specifications in the following areas without compromising functionality:

• Supply voltage range (wider ranges are acceptable)
• Operating temperature range (wider ranges are acceptable)
• Output current capability (higher ratings are acceptable)
• Product status (active or discontinued parts are acceptable alternatives to obsolete parts)

The two qualified substitute parts—CD74AC251M and CD74AC251M96—both maintain identical circuit configuration and package specifications while offering improved electrical performance and extended operating ranges compared to the 74AC251SC.

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation: CD74AC251M96

The CD74AC251M96 manufactured by Texas Instruments is the preferred substitute for the obsolete 74AC251SC. This part maintains active product status, ensuring long-term availability and supply chain stability. The CD74AC251M96 is supplied in Tape & Reel packaging and carries ROHS3 compliance certification. The extended operating temperature range (-55°C ~ 125°C) and wider supply voltage tolerance (1.5V ~ 5.5V) provide superior performance margins compared to the original specification.

Secondary Recommendation: CD74AC251M

The CD74AC251M from Texas Instruments serves as an alternative substitute, offering identical electrical specifications to the CD74AC251M96 but with discontinued product status at DiGi Electronics. This part is supplied in Tube packaging. Selection of this part should be limited to applications where supply continuity is not a primary concern.

Both substitute parts satisfy the mandatory compatibility requirements: identical 1 x 8:1 circuit configuration, 16-SOIC package form factor, and surface mount technology. The increased output current capability (75mA versus 24mA) and extended operating ranges represent performance improvements over the original design.

Frequently Asked Questions (FAQ)

Q: Can the CD74AC251M96 be used as a direct replacement for the 74AC251SC?

A: Yes. Both parts share identical circuit configuration (1 x 8:1 multiplexer), package type (16-SOIC), and mounting technology (surface mount). The CD74AC251M96 meets or exceeds all electrical specifications of the 74AC251SC.

Q: What is the difference between CD74AC251M and CD74AC251M96?

A: Both parts are manufactured by Texas Instruments and share identical electrical specifications. The primary difference is packaging: CD74AC251M is supplied in Tube format, while CD74AC251M96 is supplied in Tape & Reel format. CD74AC251M96 maintains active product status, whereas CD74AC251M is discontinued at DiGi Electronics.

Q: Are there any voltage or temperature limitations when substituting these parts?

A: No. The substitute parts operate across wider voltage ranges (1.5V ~ 5.5V versus 2V ~ 6V) and extended temperature ranges (-55°C ~ 125°C versus -40°C ~ 85°C). Applications designed for the original 74AC251SC specifications will operate within the substitute parts' operating envelope.

Q: Does the increased output current (75mA versus 24mA) affect circuit design?

A: No. Higher output current capability does not require circuit modifications. The substitute parts are fully compatible with designs engineered for the original 24mA specification.

Q: What is the significance of ROHS3 compliance on the substitute parts?

A: ROHS3 compliance indicates the substitute parts meet current environmental and material restriction standards. This certification supports regulatory compliance for new product designs and manufacturing operations.

Q: Which substitute part should be selected for new designs?

A: CD74AC251M96 is recommended for new designs due to its active product status, ensuring availability throughout the design lifecycle and production phases.