LP2951CM-3.3 Equivalent & Substitute Parts

Part Overview

The LP2951CM-3.3 is a linear voltage regulator IC in the positive adjustable (fixed) configuration, delivering 100mA output current in an 8-SOIC surface mount package. This device is classified as Not For New Designs by Texas Instruments, making identification of equivalent and substitute parts essential for ongoing production support and design continuity.

The LP2951 series provides regulated 3.3V output with integrated protection features including over-current, over-temperature, and short-circuit protection. The 0.6V maximum dropout voltage at 100mA and 120µA quiescent current make it suitable for low-power applications requiring stable voltage regulation across the -40°C to 125°C operating range.

Substiute Parts

LP2951CM-3.3

Texas InstrumentsIn Stock: 7760LP2951CM-3.3 Datasheet

Current PartRFQ

LP2951CM-3.3/NOPB

Texas InstrumentsIn Stock: 26178LP2951CM-3.3/NOPB Datasheet

DirectRFQ

LP2951ACM-3.3

National SemiconductorIn Stock: 14396LP2951ACM-3.3 Datasheet

Parametric EquivalentRFQ

LP2951ACM-3.3/NOPB

Texas InstrumentsIn Stock: 3307LP2951ACM-3.3/NOPB Datasheet

Parametric EquivalentRFQ

LP2951ACD-3.3R2G

onsemiIn Stock: 2633LP2951ACD-3.3R2G Datasheet

MFR RecommendedRFQ

LP2951CD-3.3R2G

onsemiIn Stock: 20321LP2951CD-3.3R2G Datasheet

MFR RecommendedRFQ

LP2951CS-L-3-3/TR

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

MFR RecommendedRFQ

NCV2951ACD3.3R2G

onsemiIn Stock: 2600NCV2951ACD3.3R2G Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LP2951CM-3.3 is determined by strict adherence to the following electrical and mechanical parameters:

Critical Substitution Parameters:

• Output Configuration: Positive
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Voltage - Input (Max): 30V
• Voltage - Output (Min/Fixed): 3.3V
• Current - Output: 100mA
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount

Substitute parts are grouped into three categories based on their relationship to the main part:

Direct Manufacturer Equivalent: LP2951CM-3.3/NOPB (Texas Instruments) — identical electrical specifications with NOPB (No Plumbum/Lead-Free) designation and improved RoHS3 compliance status.

Parametric Equivalents: LP2951ACM-3.3 (National Semiconductor) and LP2951ACM-3.3/NOPB (Texas Instruments) — maintain all critical electrical parameters with active product status and RoHS3 compliance.

Manufacturer Recommended Alternatives: LP2951ACD-3.3R2G, LP2951CD-3.3R2G (onsemi), LP2951CS-L-3-3/TR (MaxLinear), and NCV2951ACD3.3R2G (onsemi) — meet all critical electrical and mechanical requirements with variations in packaging format, dropout voltage performance, and supply current characteristics.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement with Improved Compliance: LP2951CM-3.3/NOPB is the primary substitute, offering identical electrical performance to the main part with active product status and ROHS3 compliance. This part maintains the same adjustable (fixed) output type and all critical electrical parameters.

For Active Product Status with Parametric Equivalence: LP2951ACM-3.3/NOPB provides full parametric equivalence with active product status, ROHS3 compliance, and tube packaging. This part is suitable for applications requiring compliance with modern environmental standards while maintaining the original electrical specifications.

For Manufacturer-Recommended Alternatives with Enhanced Performance: LP2951ACD-3.3R2G and LP2951CD-3.3R2G (onsemi) offer improved dropout voltage performance (0.45V vs. 0.6V) and reduced supply current (12mA vs. 14mA), with ROHS3 compliance and active product status. These parts are available in Cut Tape and Tape & Reel packaging formats respectively.

For Automotive-Grade Applications: NCV2951ACD3.3R2G is the automotive-qualified variant (AEC-Q100) from onsemi, suitable for applications requiring automotive-grade components with ROHS3 compliance and active product status.

For Alternative Manufacturer Source: LP2951CS-L-3-3/TR (MaxLinear) provides an alternative source with active product status and RoHS compliance. Note the slightly elevated quiescent current (170µA vs. 120µA) and enable control feature availability.

Frequently Asked Questions (FAQ)

Q: Can LP2951CM-3.3/NOPB be used as a direct replacement for LP2951CM-3.3?

A: Yes. LP2951CM-3.3/NOPB is electrically and mechanically identical to the main part, with the primary difference being the NOPB designation indicating lead-free construction and improved RoHS3 compliance status. Both parts maintain the same 8-SOIC package, 100mA output current, and 0.6V dropout voltage specification.

Q: What is the difference between adjustable (fixed) and fixed output types?

A: The main part LP2951CM-3.3 is specified as adjustable (fixed), indicating it can be configured for fixed 3.3V output through external resistor networks. The manufacturer-recommended alternatives (LP2951ACD-3.3R2G, LP2951CD-3.3R2G, LP2951CS-L-3-3/TR, NCV2951ACD3.3R2G) are specified as fixed output type, meaning they deliver a fixed 3.3V output without external configuration requirements. Both configurations deliver the same 3.3V output voltage for this product line.

Q: Are the onsemi LP2951ACD-3.3R2G and LP2951CD-3.3R2G interchangeable?

A: Yes, electrically and functionally. The primary difference is packaging format: LP2951ACD-3.3R2G is supplied in Cut Tape (CT) & Digi-Reel® format, while LP2951CD-3.3R2G is supplied in Tape & Reel (TR) format. Both parts are identical in electrical performance, dropout voltage (0.45V), and supply current (12mA).

Q: What is the significance of the improved dropout voltage in onsemi parts?

A: The onsemi variants (LP2951ACD-3.3R2G, LP2951CD-3.3R2G, LP2951CS-L-3-3/TR, NCV2951ACD3.3R2G) specify 0.45V maximum dropout voltage compared to 0.6V in the main part. This 0.15V improvement allows operation with lower input voltages or provides better regulation margin in applications with tight input voltage constraints.

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

A: Yes. NCV2951ACD3.3R2G is automotive-qualified (AEC-Q100) but can be used in non-automotive applications. The automotive qualification represents an additional quality and reliability assurance level, making it suitable for any application requiring the same electrical specifications.

Q: What packaging considerations apply when selecting a substitute?

A: All substitute parts use the 8-SOIC (0.154", 3.90mm Width) package, ensuring PCB footprint compatibility. Packaging format differences (Tube, Cut Tape & Digi-Reel®, Tape & Reel) affect handling and assembly processes but not electrical or mechanical compatibility. Select based on your assembly equipment and supply chain requirements.

Q: Why is the main part LP2951CM-3.3 marked as Not For New Designs?

A: This designation indicates Texas Instruments has transitioned this part to end-of-life status. For new designs, use LP2951CM-3.3/NOPB or LP2951ACM-3.3/NOPB (both active status) for continued support and compliance with modern environmental standards. For existing designs, all listed substitutes provide equivalent or improved performance.