LP2951ACD-3.3G Equivalent & Substitute Parts

Part Overview

The LP2951ACD-3.3G is a linear voltage regulator IC from onsemi, delivering a fixed 3.3V output at 100mA in an 8-SOIC surface mount package. This device is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement continuity. The part operates across the industrial temperature range of -40°C to 125°C and includes integrated over-current and over-temperature protection.

Substiute Parts

LP2951ACD-3.3G

onsemiIn Stock: 3803LP2951ACD-3.3G Datasheet

Current PartRFQ

LP2951ACM-3.3/NOPB

Texas InstrumentsIn Stock: 3307LP2951ACM-3.3/NOPB Datasheet

SimilarRFQ

LP2951ACMX-3.3/NOPB

Texas InstrumentsIn Stock: 163442LP2951ACMX-3.3/NOPB Datasheet

SimilarRFQ

LP2951CM-3.3/NOPB

Texas InstrumentsIn Stock: 26178LP2951CM-3.3/NOPB Datasheet

SimilarRFQ

LP2951CMX-3.3/NOPB

Texas InstrumentsIn Stock: 30192LP2951CMX-3.3/NOPB Datasheet

SimilarRFQ

LP2951CS-L-3-3/TR

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

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the LP2951ACD-3.3G is determined by the following critical parameters:

• Output voltage: 3.3V fixed
• Output current capability: 100mA minimum
• Package: 8-SOIC form factor
• Input voltage rating: 30V maximum
• Dropout voltage: 0.45V @ 100mA or lower
• Operating temperature range: -40°C to 125°C
• Protection: Over-current and over-temperature capability
• Compliance: RoHS3 compliance required

Substitute parts are grouped into two categories based on output type configuration:

Category 1: Fixed Output (Direct Equivalents) Parts with fixed 3.3V output matching the original specification exactly. These include LP2951CS-L-3-3/TR from MaxLinear, Inc.

Category 2: Adjustable Output (Fixed Configuration) Parts with adjustable output architecture configured to 3.3V fixed output. These include LP2951ACM-3.3/NOPB, LP2951ACMX-3.3/NOPB, LP2951CM-3.3/NOPB, and LP2951CMX-3.3/NOPB from Texas Instruments. While architecturally adjustable, these parts are factory-configured to deliver 3.3V fixed output and meet all electrical and mechanical requirements.

Parameter Comparison

Engineering Selection Recommendations

All substitute parts listed maintain active product status with established manufacturer support, addressing the obsolescence of the original LP2951ACD-3.3G. Selection among substitutes should be based on the following factors:

Texas Instruments LP2951 Series (ACM, ACMX, CM, CMX variants): These parts offer the lowest quiescent current matching the original specification at 120 µA and include enhanced short-circuit protection. The ACMX and CMX variants feature Cut Tape and Digi-Reel packaging with significantly higher inventory availability (163,395 and 30,100 units respectively), supporting high-volume procurement. All variants maintain ROHS3 compliance.

MaxLinear LP2951CS-L-3-3/TR: This part provides an exact fixed-output architecture matching the original design intent. It maintains the original 0.45V dropout specification and operates at 170 µA quiescent current. Tape & Reel packaging is standard. RoHS compliance is confirmed. Inventory availability is moderate at 7,163 units.

The Texas Instruments variants introduce a 0.15V higher dropout voltage (0.6V vs. 0.45V) and add short-circuit protection not present in the original. These trade-offs are acceptable in most applications and provide superior long-term supply chain stability.

Frequently Asked Questions (FAQ)

Q: Can I use LP2951ACM-3.3/NOPB as a direct replacement for LP2951ACD-3.3G?

A: Yes. Both parts deliver 3.3V fixed output at 100mA in an 8-SOIC package with identical operating temperature range and quiescent current. The primary difference is a 0.15V higher dropout voltage (0.6V vs. 0.45V) and the addition of short-circuit protection. These differences are compatible with most circuit designs.

Q: What is the difference between LP2951ACMX-3.3/NOPB and LP2951CM-3.3/NOPB?

A: Both parts are electrically identical. The difference is packaging: ACMX uses Cut Tape & Digi-Reel format with 163,395 units in stock, while CM uses Tube packaging with 26,145 units in stock. Select based on your procurement and assembly requirements.

Q: Why does LP2951CS-L-3-3/TR have higher quiescent current (170 µA vs. 120 µA)?

A: This is a manufacturing characteristic of the MaxLinear variant. The 50 µA difference represents approximately 0.165mW additional power consumption at 3.3V, which is negligible in most applications. This part maintains the original 0.45V dropout specification.

Q: Are all substitute parts RoHS compliant?

A: Yes. All listed substitutes maintain RoHS compliance. The original part is ROHS3 compliant, and all substitutes meet or exceed this standard.

Q: Can I mix packaging types in production?

A: Yes, provided your assembly process accommodates both formats. Cut Tape & Digi-Reel (ACMX, CMX) and Tube (ACM, CM) formats are compatible with standard surface mount assembly equipment. Tape & Reel (TR) format used by MaxLinear is also standard. Verify your feeder compatibility with your contract manufacturer.

Q: What happens if my circuit requires the exact 0.45V dropout specification?

A: Use LP2951CS-L-3-3/TR from MaxLinear, which maintains the original 0.45V dropout voltage. Texas Instruments variants operate at 0.6V dropout, which may require circuit redesign if dropout margin is critical.