LP2951CM-3.0 Linear Voltage Regulator Equivalent & Substitute Parts

Part Overview

The LP2951CM-3.0 is a linear voltage regulator IC from Texas Instruments designed for positive adjustable (fixed) output applications with 100mA current capacity in an 8-SOIC surface mount package. This part is classified as obsolete, making equivalent and substitute parts necessary for ongoing production and maintenance applications. The LP2951 series provides regulated power management with integrated protection features including over-current, over-temperature, and short-circuit protection across an operating temperature range of -40°C to 125°C.

Substiute Parts

LP2951CM-3.0

Texas InstrumentsIn Stock: 2063LP2951CM-3.0 Datasheet

Current PartRFQ

LP2951CM-3.0/NOPB

National SemiconductorIn Stock: 1981LP2951CM-3.0/NOPB Datasheet

DirectRFQ

LP2951ACM-3.0/NOPB

Texas InstrumentsIn Stock: 8896LP2951ACM-3.0/NOPB Datasheet

Parametric EquivalentRFQ

LP2951ACD-3.0R2G

onsemiIn Stock: 6361LP2951ACD-3.0R2G Datasheet

MFR RecommendedRFQ

LP2951CD-3.0G

onsemiIn Stock: 975LP2951CD-3.0G Datasheet

MFR RecommendedRFQ

LP2951CD-3.0R2G

onsemiIn Stock: 8558LP2951CD-3.0R2G Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the LP2951CM-3.0 is determined by strict adherence to the following electrical and mechanical parameters:

Critical Substitution Parameters:

• Package / Case: 8-SOIC (0.154", 3.90mm Width) — mechanical compatibility requirement
• Voltage - Input (Max): 30V — input voltage rating
• Voltage - Output (Min/Fixed): 1.235V (3V) — output voltage specification
• Current - Output: 100mA — output current capacity
• Operating Temperature: -40°C ~ 125°C — thermal operating range
• Output Configuration: Positive — polarity requirement
• Protection Features: Over Current, Over Temperature, Short Circuit — safety feature set

Substitute parts are grouped into two categories:

Direct Manufacturer Equivalent: Parts with identical electrical specifications and packaging, differing only in packaging format (Bulk vs. Tube) or manufacturer designation suffix.

Parametric Equivalent: Parts meeting all critical electrical and mechanical parameters with minor variations in specific characteristics (such as dropout voltage or control features) that do not affect functional compatibility in standard applications.

Parameter Comparison

Engineering Selection Recommendations

For Active Production (RoHS3 Compliance Required):

LP2951ACM-3.0/NOPB (Texas Instruments, Tube packaging) is the primary recommended substitute. This part maintains identical electrical specifications to the original LP2951CM-3.0, including adjustable output type, 0.6V dropout voltage, and enable control feature. The part is currently active with ROHS3 compliance certification, making it suitable for new designs and ongoing production requiring regulatory compliance.

LP2951CD-3.0R2G (onsemi, Cut Tape packaging) is an alternative active substitute with ROHS3 compliance. This part operates with a lower dropout voltage (0.45V @ 100mA) and fixed output type, eliminating the enable control feature. Selection of this part is appropriate for applications where the fixed 3V output and reduced dropout voltage provide design advantages.

For Legacy System Maintenance (RoHS Compliance Not Required):

LP2951CM-3.0/NOPB (National Semiconductor, Bulk packaging) provides direct electrical equivalence with identical specifications. This part is active and suitable for replacement in existing systems where RoHS compliance is not mandated.

LP2951CD-3.0G (onsemi, Tube packaging) is classified as obsolete and should be avoided for new procurement despite ROHS3 compliance certification.

Frequently Asked Questions (FAQ)

Q: Can LP2951ACM-3.0/NOPB be used as a direct replacement for LP2951CM-3.0?

A: Yes. Both parts share identical electrical specifications including 30V maximum input voltage, 1.235V to 29V output range, 100mA output current, 0.6V dropout voltage, and enable control feature. The 8-SOIC package is mechanically identical. The primary difference is product status (Active vs. Obsolete) and RoHS compliance (ROHS3 vs. non-compliant).

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

A: The LP2951CM-3.0 and LP2951ACM-3.0/NOPB feature adjustable (fixed) output type with enable control, allowing output voltage configuration. The LP2951CD variants feature fixed 3V output type without enable control. Selection depends on whether your application requires output voltage adjustment capability.

Q: Are the onsemi LP2951CD variants compatible with the original Texas Instruments part?

A: The onsemi LP2951CD-3.0R2G and LP2951ACD-3.0R2G are parametrically equivalent with the same 8-SOIC package, 30V input rating, 100mA output current, and -40°C to 125°C operating range. However, they feature fixed 3V output (not adjustable), lower dropout voltage (0.45V vs. 0.6V), and lack enable control. These differences may affect circuit compatibility depending on application requirements.

Q: What packaging options are available for LP2951 substitutes?

A: Substitute parts are available in three packaging formats: Bulk (LP2951CM-3.0/NOPB), Tube (LP2951ACM-3.0/NOPB, LP2951CD-3.0G), and Cut Tape (LP2951ACD-3.0R2G, LP2951CD-3.0R2G). All maintain the same 8-SOIC (0.154", 3.90mm Width) case outline. Packaging selection is determined by procurement and assembly requirements.

Q: Should I select an active or obsolete substitute part?

A: Active parts are recommended for new designs and ongoing production to ensure long-term availability and supply chain stability. Obsolete parts should be used only for legacy system maintenance where active alternatives are not suitable or available.

Q: Does RoHS compliance affect electrical performance?

A: RoHS compliance certification does not alter electrical performance. ROHS3-compliant parts (LP2951ACM-3.0/NOPB, LP2951CD-3.0R2G, LP2951ACD-3.0R2G, LP2951CD-3.0G) meet the same electrical specifications as non-compliant parts. Compliance status is a regulatory and procurement consideration, not a functional parameter.