LP2951-33D Linear Voltage Regulator Equivalent & Substitute Parts

Part Overview

The LP2951-33D is a linear voltage regulator IC from Texas Instruments designed for positive adjustable (fixed) output applications with 100mA current capability in an 8-SOIC surface mount package. This component is classified as Last Time Buy, indicating discontinued production status. Finding equivalent and substitute parts is necessary to ensure design continuity and maintain supply chain reliability for applications currently using this regulator.

Substiute Parts

LP2951-33D

Texas InstrumentsIn Stock: 65338LP2951-33D Datasheet

Current PartRFQ

LP2951-33DR

Texas InstrumentsIn Stock: 65495LP2951-33DR Datasheet

MFR RecommendedRFQ

LP2951CS-L-3-3/TR

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

MFR RecommendedRFQ

RT2560Q-33GSP

Richtek USA Inc.In Stock: 1762RT2560Q-33GSP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LP2951-33D is determined by the following critical parameters:

Electrical Compatibility Requirements:

• Output Configuration: Positive
• Current - Output: 100mA minimum
• Voltage - Input (Max): 30V or greater
• Voltage - Output (Min/Fixed): Compatible with 3.3V fixed or adjustable to 3.3V
• Voltage Dropout (Max): 0.6V or lower @ 100mA
• Operating Temperature: -40°C ~ 125°C minimum range
• Protection Features: Over Current and Over Temperature protection required

Mechanical Compatibility Requirements:

• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (0.154", 3.90mm Width) or equivalent footprint

Compliance Requirements:

• RoHS Status: ROHS3 Compliant or equivalent
• Moisture Sensitivity Level (MSL): 1 (Unlimited) preferred

The identified substitute parts meet these criteria with variations in packaging format (Cut Tape vs. Tape & Reel) and manufacturer source, while maintaining functional and electrical equivalence.

Parameter Comparison

Engineering Selection Recommendations

LP2951-33DR (Texas Instruments)

This is the manufacturer-recommended direct substitute from Texas Instruments. It maintains identical electrical specifications and operating parameters to the LP2951-33D while offering Active product status. The primary difference is packaging format (Cut Tape & Digi-Reel® versus Tube). This part is preferred for designs requiring continuity with the original component specifications and manufacturer support. ROHS3 compliance and unlimited moisture sensitivity level (MSL 1) are maintained.

LP2951CS-L-3-3/TR (MaxLinear, Inc.)

This substitute provides fixed 3.3V output with improved dropout voltage (0.45V @ 100mA) compared to the main part. It is suitable for applications where the adjustable output feature of the LP2951-33D is not required and lower dropout performance is beneficial. The higher quiescent current (170 µA versus 120 µA) should be evaluated for battery-powered applications. Active product status and RoHS compliance are confirmed.

RT2560Q-33GSP (Richtek USA Inc.)

This substitute offers the lowest quiescent current (5 µA) among the alternatives, making it advantageous for low-power or battery-operated designs. It features an exposed pad package variant and higher maximum input voltage (36V). However, the operating temperature range is limited to -40°C ~ 85°C, which is narrower than the main part. This part carries AEC-Q100 automotive qualification and ROHS3 compliance. Selection should be based on temperature range requirements and the benefit of ultra-low quiescent current for the specific application.

Frequently Asked Questions (FAQ)

Q: Can LP2951-33DR be used as a direct replacement for LP2951-33D?

A: Yes. The LP2951-33DR is the manufacturer-recommended substitute from Texas Instruments with identical electrical specifications, output configuration, current rating, voltage parameters, and protection features. The only difference is packaging format (Cut Tape & Digi-Reel® versus Tube). PCB footprint and pinout are identical.

Q: What is the key difference between LP2951CS-L-3-3/TR and the main part?

A: The LP2951CS-L-3-3/TR has a fixed 3.3V output rather than adjustable output. It also features improved dropout voltage (0.45V @ 100mA versus 0.6V @ 100mA). This part is suitable only for applications that do not require output voltage adjustment.

Q: Is RT2560Q-33GSP compatible with the LP2951-33D?

A: RT2560Q-33GSP is electrically compatible for 3.3V fixed output applications with identical current rating and package footprint. However, its operating temperature range (-40°C ~ 85°C) is narrower than the main part (-40°C ~ 125°C). Selection depends on whether your application requires the full temperature range. The RT2560Q-33GSP offers significantly lower quiescent current (5 µA), which may be advantageous for power-sensitive designs.

Q: Are all substitute parts RoHS compliant?

A: Yes. All identified substitutes are RoHS compliant (ROHS3 or equivalent). The LP2951-33D is ROHS3 compliant, LP2951-33DR is ROHS3 compliant, LP2951CS-L-3-3/TR is RoHS compliant, and RT2560Q-33GSP is ROHS3 compliant.

Q: What packaging formats are available for these parts?

A: LP2951-33D is supplied in Tube format. LP2951-33DR is available in Cut Tape (CT) & Digi-Reel® format. LP2951CS-L-3-3/TR and RT2560Q-33GSP are supplied in Tape & Reel (TR) format. All parts use the same 8-SOIC surface mount package footprint.

Q: Which substitute should I choose for a new design?

A: For designs requiring adjustable output capability and full -40°C ~ 125°C temperature range, use LP2951-33DR. For fixed 3.3V output with improved dropout performance, use LP2951CS-L-3-3/TR. For ultra-low quiescent current applications with fixed 3.3V output and automotive qualification, use RT2560Q-33GSP, provided the -40°C ~ 85°C temperature range is acceptable.