LP2951CD Linear Voltage Regulator IC Equivalent & Substitute Parts

Part Overview

The LP2951CD is a linear voltage regulator IC from onsemi designed for positive adjustable (fixed) output applications with 100mA current capability in an 8-SOIC surface mount package. This device is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and production continuity. The LP2951CD operates across a wide input voltage range (up to 30V) and supports adjustable or fixed output configurations, with integrated over-current and over-temperature protection.

Substiute Parts

LP2951CD

onsemiIn Stock: 5311LP2951CD Datasheet

Current PartRFQ

LP2951CS-L-5-0/TR

MaxLinear, Inc.In Stock: 2720LP2951CS-L-5-0/TR Datasheet

DirectRFQ

LP2951-50QDRQ1

Texas InstrumentsIn Stock: 23497LP2951-50QDRQ1 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 LP2951CD is determined by the following critical parameters:

• Package compatibility: 8-SOIC surface mount form factor
• Output configuration: Positive polarity
• Output type: Adjustable (Fixed) capability
• Current rating: 100mA minimum
• Input voltage range: 30V maximum
• Output voltage range: 1.235V to 30V
• Operating temperature: -40°C to 125°C
• Protection features: Over-current and over-temperature protection

Substitute parts must maintain compatibility across these parameters. Variations in quiescent current, dropout voltage, and control features (such as Enable pins) do not prevent substitution when the core electrical and mechanical specifications align. Product status and RoHS compliance are secondary considerations that may influence selection based on application requirements and regulatory constraints.

Parameter Comparison

Engineering Selection Recommendations

LP2951CS-L-5-0/TR (MaxLinear, Inc.) is a direct functional equivalent suitable for applications requiring adjustable or fixed 5V output. This part maintains identical dropout voltage and quiescent current specifications to the original LP2951CD, with the advantage of active product status and RoHS compliance. Packaging is Tape & Reel format.

LP2951-50QDRQ1 (Texas Instruments) provides an alternative with automotive-grade qualification (AEC-Q100) and enhanced short-circuit protection. This part is suitable for automotive and industrial applications requiring higher reliability standards. Dropout voltage is slightly higher at 0.6V, and quiescent current matches the original specification. Product status is active with ROHS3 compliance.

LP2951CS-L-3-3/TR (MaxLinear, Inc.) is a fixed 3.3V output variant suitable only for applications specifically requiring 3.3V regulation. This part is not interchangeable with the original LP2951CD in adjustable output configurations. It maintains equivalent dropout voltage and protection features, with active product status and RoHS compliance.

All three substitute parts are available in active production status, addressing the obsolescence of the original LP2951CD. Selection should prioritize application-specific output voltage requirements and regulatory compliance needs.

Frequently Asked Questions (FAQ)

Q: Can LP2951CS-L-5-0/TR directly replace LP2951CD in all applications?

A: Yes, for applications using adjustable or fixed 5V output configurations. Both parts share identical package geometry (8-SOIC), output current rating (100mA), input voltage range (30V maximum), and dropout voltage specification (0.45V @ 100mA). The substitute has active product status and RoHS compliance, making it suitable for new designs and production continuity.

Q: What is the difference between LP2951CS-L-5-0/TR and LP2951CS-L-3-3/TR?

A: The primary difference is output voltage configuration. LP2951CS-L-5-0/TR supports adjustable or fixed 5V output, while LP2951CS-L-3-3/TR is fixed at 3.3V output only. Both share identical package, current rating, and protection features. Selection depends on the specific output voltage requirement of your application.

Q: Why does LP2951-50QDRQ1 have a higher dropout voltage (0.6V vs 0.45V)?

A: LP2951-50QDRQ1 is qualified to automotive standards (AEC-Q100) and includes enhanced short-circuit protection. The slightly higher dropout voltage is a characteristic of this variant but remains within acceptable limits for most applications. This part is recommended for automotive and high-reliability applications.

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

A: No. LP2951CS-L-5-0/TR and LP2951CS-L-3-3/TR are supplied in Tape & Reel (TR) format, while LP2951-50QDRQ1 is supplied in Cut Tape (CT) & Digi-Reel format. All three maintain the same 8-SOIC package geometry suitable for surface mount assembly.

Q: Can I use these substitutes in RoHS-compliant applications?

A: Yes. LP2951CS-L-5-0/TR, LP2951-50QDRQ1, and LP2951CS-L-3-3/TR are all RoHS compliant (RoHS or ROHS3), making them suitable for applications with RoHS requirements. The original LP2951CD is RoHS non-compliant.

Q: What is the quiescent current difference between LP2951CD and the substitutes?

A: LP2951CD and LP2951-50QDRQ1 both specify 120 µA quiescent current. LP2951CS-L-5-0/TR and LP2951CS-L-3-3/TR specify 170 µA. This 50 µA difference is negligible in most applications but should be considered in battery-powered or ultra-low-power designs.