LP2951CMX-3.3 Equivalent & Substitute Parts

Part Overview

The LP2951CMX-3.3 is a linear voltage regulator IC from Texas Instruments, classified as a Power Management (PMIC) component. This device provides positive adjustable (fixed) output regulation at 3.3V with 100mA output capability in an 8-SOIC surface mount package. The main part is currently listed as obsolete, making equivalent and substitute parts necessary for ongoing design support and production continuity.

Substiute Parts

LP2951CMX-3.3

Texas InstrumentsIn Stock: 3966LP2951CMX-3.3 Datasheet

Current PartRFQ

LP2951CMX-3.3/NOPB

Texas InstrumentsIn Stock: 30192LP2951CMX-3.3/NOPB Datasheet

DirectRFQ

LP2951ACMX-3.3/NOPB

Texas InstrumentsIn Stock: 163442LP2951ACMX-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 for the LP2951CMX-3.3 is determined by the following critical parameters:

• Package / Case: 8-SOIC (0.154", 3.90mm Width) — all substitutes must match this form factor
• Output Configuration: Positive
• Number of Regulators: 1
• Voltage - Input (Max): 30V
• Voltage - Output (Min/Fixed): 1.235V (3.3V)
• Current - Output: 100mA
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount

Substitute parts are grouped into two categories:

Direct Manufacturer Equivalents (Texas Instruments): Parts with identical electrical specifications and active product status, offering direct replacement capability with improved compliance.

Manufacturer Recommended Alternatives (onsemi, MaxLinear): Parts meeting core electrical and mechanical requirements with active product status and RoHS3 compliance, suitable for new designs and production continuity.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Active Texas Instruments Parts):

LP2951CMX-3.3/NOPB and LP2951ACMX-3.3/NOPB are the primary substitutes, offering identical electrical specifications to the obsolete LP2951CMX-3.3. Both are active products with ROHS3 compliance, making them suitable for new production and designs requiring regulatory compliance. LP2951CMX-3.3/NOPB has higher inventory availability (30,100 pcs), while LP2951ACMX-3.3/NOPB offers extended inventory (163,395 pcs).

For Manufacturer Recommended Alternatives:

LP2951ACD-3.3R2G and LP2951CD-3.3R2G (onsemi) provide fixed 3.3V output with improved dropout voltage (0.45V vs. 0.6V) and reduced supply current (12 mA vs. 14 mA). These parts are active, ROHS3 compliant, and suitable for applications where lower dropout performance is beneficial.

LP2951CS-L-3-3/TR (MaxLinear) offers fixed 3.3V output with Enable control feature and RoHS compliance. Quiescent current is 170 µA, higher than the main part specification.

NCV2951ACD3.3R2G (onsemi) is an automotive-grade variant (AEC-Q100 qualified) with fixed 3.3V output, suitable for automotive applications requiring automotive qualification.

All substitute parts maintain the 8-SOIC package form factor, 100mA output capability, and -40°C to 125°C operating temperature range of the original part.

Frequently Asked Questions (FAQ)

Q: Can LP2951CMX-3.3/NOPB be used as a direct replacement for LP2951CMX-3.3?

A: Yes. LP2951CMX-3.3/NOPB is a direct equivalent with identical electrical specifications, same 8-SOIC package, and active product status. The primary difference is improved RoHS3 compliance.

Q: What is the difference between adjustable and fixed output types in the substitute list?

A: The original LP2951CMX-3.3 and its Texas Instruments equivalents (LP2951CMX-3.3/NOPB, LP2951ACMX-3.3/NOPB) feature adjustable (fixed) output, allowing configuration flexibility. The onsemi and MaxLinear alternatives (LP2951ACD-3.3R2G, LP2951CD-3.3R2G, LP2951CS-L-3-3/TR, NCV2951ACD3.3R2G) are fixed 3.3V output devices. Both types deliver 3.3V in standard configurations but differ in design flexibility.

Q: Are all substitute parts available in the same packaging format?

A: All substitute parts use the 8-SOIC (0.154", 3.90mm Width) surface mount package. Packaging options vary: LP2951CMX-3.3/NOPB and LP2951ACMX-3.3/NOPB are available in Cut Tape (CT) & Digi-Reel®, while LP2951ACD-3.3R2G, LP2951CD-3.3R2G, LP2951CS-L-3-3/TR, and NCV2951ACD3.3R2G are available in Tape & Reel (TR) format.

Q: Which substitute offers the best dropout voltage performance?

A: LP2951ACD-3.3R2G, LP2951CD-3.3R2G, LP2951CS-L-3-3/TR, and NCV2951ACD3.3R2G all provide 0.45V maximum dropout at 100mA, compared to 0.6V for the original part and its Texas Instruments equivalents.

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

A: Yes. NCV2951ACD3.3R2G is automotive-grade and AEC-Q100 qualified, making it appropriate for automotive circuit designs requiring automotive-qualified components.

Q: What is the inventory status of these substitute parts?

A: LP2951ACMX-3.3/NOPB has the highest inventory (163,395 pcs), followed by LP2951CD-3.3R2G (20,300 pcs) and LP2951CMX-3.3/NOPB (30,100 pcs). All listed substitutes are in active production with new original stock available.