LP2951ACD-3.3R2 Equivalent & Substitute Parts

Part Overview

The LP2951ACD-3.3R2 is a linear voltage regulator IC from onsemi, delivering a fixed 3.3V output at 100mA with 8-SOIC surface mount packaging. This part is classified as obsolete, making equivalent and substitute parts necessary for new designs and production continuity. The device provides over-current and over-temperature protection across an operating range of -40°C to 125°C, with a maximum input voltage of 30V and dropout voltage of 0.45V at full load.

Substiute Parts

LP2951ACD-3.3R2

onsemiIn Stock: 905LP2951ACD-3.3R2 Datasheet

Current PartRFQ

LP2951ACD-3.3R2G

onsemiIn Stock: 2633LP2951ACD-3.3R2G Datasheet

DirectRFQ

LP2951CD-3.3R2G

onsemiIn Stock: 20321LP2951CD-3.3R2G Datasheet

Parametric EquivalentRFQ

NCV2951ACD3.3R2G

onsemiIn Stock: 2600NCV2951ACD3.3R2G Datasheet

Parametric EquivalentRFQ

LP2951ACM-3.3/NOPB

Texas InstrumentsIn Stock: 3307LP2951ACM-3.3/NOPB Datasheet

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LP2951ACMX-3.3/NOPB

Texas InstrumentsIn Stock: 163442LP2951ACMX-3.3/NOPB Datasheet

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LP2951CM-3.3/NOPB

Texas InstrumentsIn Stock: 26178LP2951CM-3.3/NOPB Datasheet

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LP2951CMX-3.3/NOPB

Texas InstrumentsIn Stock: 30192LP2951CMX-3.3/NOPB Datasheet

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LP2951CS-L-3-3/TR

MaxLinear, Inc.In Stock: 7183LP2951CS-L-3-3/TR Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution for the LP2951ACD-3.3R2 is determined by electrical and mechanical compatibility across the following critical parameters: fixed 3.3V output voltage, 100mA output current capability, 30V maximum input voltage, 0.45V dropout voltage specification, 8-SOIC package footprint, and -40°C to 125°C operating temperature range. Parts are grouped into three categories based on their relationship to the main part:

Direct Manufacturer Equivalents (onsemi): Parts with identical electrical specifications and the same base product number (LP2951), differing only in packaging format or product status. These maintain full pin and functional compatibility.

Parametric Equivalents (onsemi): Parts meeting all electrical and thermal specifications with identical package geometry, suitable for direct substitution in existing designs.

Similar Parts (Texas Instruments, MaxLinear): Parts from alternative manufacturers with matching output voltage, current rating, package, and operating temperature, though some may have different output type configurations (adjustable vs. fixed) or slightly different protection feature sets.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Highest Compatibility): LP2951ACD-3.3R2G and LP2951CD-3.3R2G are the primary substitutes, both from onsemi with identical electrical specifications and active product status. LP2951ACD-3.3R2G is available in Cut Tape and Digi-Reel packaging, while LP2951CD-3.3R2G is supplied in Tape & Reel format. Both are ROHS3 compliant, addressing regulatory requirements where the original obsolete part does not.

For Automotive Applications: NCV2951ACD3.3R2G is qualified to AEC-Q100 automotive standards and maintains all electrical specifications of the original part. This variant is suitable for automotive-grade designs requiring enhanced reliability qualification.

For Alternative Manufacturer Selection: Texas Instruments LP2951 variants (ACM, ACMX, CM, CMX) provide active product status and ROHS3 compliance. These parts feature adjustable output type with fixed 3.3V configuration and slightly higher dropout voltage (0.6V vs. 0.45V). MaxLinear LP2951CS-L-3-3/TR offers fixed output matching the original specification with RoHS compliance and higher quiescent current (170 µA vs. 120 µA).

Packaging Considerations: Select packaging format based on assembly requirements: Cut Tape (CT) & Digi-Reel for automated pick-and-place operations, Tape & Reel (TR) for high-volume production, or Tube for lower-volume manual assembly.

Frequently Asked Questions (FAQ)

Q: Can LP2951ACD-3.3R2G directly replace LP2951ACD-3.3R2 in existing designs?

A: Yes. LP2951ACD-3.3R2G is electrically and mechanically identical to the obsolete LP2951ACD-3.3R2, with the same 3.3V output, 100mA current rating, 8-SOIC package, and operating temperature range. The primary difference is active product status and ROHS3 compliance.

Q: What is the difference between fixed and adjustable output types in the LP2951 family?

A: Fixed output parts (LP2951ACD-3.3R2G, LP2951CD-3.3R2G, LP2951CS-L-3-3/TR) deliver a preset 3.3V output without external configuration. Adjustable output parts (Texas Instruments variants) allow output voltage adjustment through external resistor networks but are factory-configured to 3.3V in the specified part numbers. Both are functionally equivalent for 3.3V applications.

Q: Are there differences in dropout voltage between substitute options?

A: Yes. The original part and onsemi/MaxLinear substitutes specify 0.45V dropout at 100mA. Texas Instruments variants specify 0.6V dropout. This 0.15V difference may impact designs operating with tight input voltage margins.

Q: Which substitute is recommended for new production designs?

A: LP2951ACD-3.3R2G or LP2951CD-3.3R2G from onsemi are recommended for new designs, as they maintain all original electrical specifications while providing active product status and ROHS3 compliance. Selection between these two depends on packaging format requirements.

Q: Is NCV2951ACD3.3R2G suitable for non-automotive applications?

A: Yes. NCV2951ACD3.3R2G meets all electrical specifications for general-purpose applications. The AEC-Q100 automotive qualification provides additional reliability assurance and does not restrict use in non-automotive designs.

Q: What packaging formats are available for each substitute?

A: LP2951ACD-3.3R2G is supplied in Cut Tape and Digi-Reel format. LP2951CD-3.3R2G is supplied in Tape & Reel. Texas Instruments variants are available in Tube (ACM, CM) or Cut Tape/Digi-Reel (ACMX, CMX) formats. MaxLinear LP2951CS-L-3-3/TR is supplied in Tape & Reel format.