LP2951-30D Equivalent & Substitute Parts

Part Overview

The LP2951-30D 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 device is classified as Last Time Buy, indicating end-of-life status. Finding equivalent and substitute parts is necessary to ensure design continuity and maintain supply chain reliability for new production runs and long-term support.

Substiute Parts

LP2951-30D

Texas InstrumentsIn Stock: 2754LP2951-30D Datasheet

Current PartRFQ

LP2951DR

Texas InstrumentsIn Stock: 55119LP2951DR 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 LP2951-30D is determined by the following critical parameters:

Primary Compatibility Criteria:

• Package / Case: 8-SOIC (0.154", 3.90mm Width) — mechanical and electrical interface compatibility
• Output Configuration: Positive
• Number of Regulators: 1
• Current - Output: 100mA minimum
• Voltage - Input (Max): 30V or greater
• Operating Temperature Range: -40°C ~ 125°C or broader
• Protection Features: Over Current and Over Temperature minimum

Secondary Compatibility Criteria:

• Voltage Dropout: Lower or equal values preferred for efficiency
• Current - Quiescent (Iq): Lower values preferred for power consumption
• Control Features: Enable function required
• RoHS Compliance: ROHS3 or equivalent

The substitute parts listed below meet these criteria with variations in output voltage configuration (fixed vs. adjustable) and minor differences in quiescent current and dropout voltage specifications.

Parameter Comparison

Engineering Selection Recommendations

LP2951DR (Texas Instruments) This part is the direct manufacturer-recommended substitute from Texas Instruments. It maintains identical electrical specifications and package format while offering Active product status. Selection of LP2951DR ensures continuity with the original design intent and manufacturer support. This is the preferred choice for designs requiring adjustable or 5V fixed output configurations.

LP2951CS-L-3-3/TR (MaxLinear, Inc.) This substitute provides a fixed 3.3V output variant with improved dropout voltage (0.45V vs. 0.6V), resulting in lower power dissipation. It is suitable for applications specifically requiring 3.3V regulation. The higher quiescent current (170 µA vs. 120 µA) should be evaluated for battery-powered or ultra-low-power applications. Active product status ensures long-term availability.

RT2560Q-33GSP (Richtek USA Inc.) This part offers the lowest quiescent current (5 µA) among substitutes, making it advantageous for power-sensitive applications. It features an exposed pad for improved thermal performance and higher maximum input voltage (36V). However, the operating temperature range is limited to -40°C ~ 85°C, and the absence of an Enable control feature may restrict functionality in designs requiring output enable/disable capability. This part carries AEC-Q100 automotive qualification. Selection requires verification that the reduced temperature range and missing Enable feature are compatible with the target application.

Frequently Asked Questions (FAQ)

Q: Can LP2951DR be used as a direct replacement for LP2951-30D? A: Yes. LP2951DR is the manufacturer-recommended substitute from Texas Instruments with identical electrical specifications, package format, and protection features. It is the preferred choice for direct substitution.

Q: What is the difference between adjustable and fixed output types? A: The LP2951-30D and LP2951DR support both adjustable and fixed output configurations through external resistor networks. The LP2951CS-L-3-3/TR and RT2560Q-33GSP are fixed-output devices preset to 3.3V. Adjustable variants offer design flexibility; fixed variants simplify board design and reduce component count.

Q: Is LP2951CS-L-3-3/TR compatible with designs requiring 5V output? A: No. LP2951CS-L-3-3/TR is fixed at 3.3V output. For 5V applications, use LP2951DR configured for 5V output or the original LP2951-30D.

Q: Why does RT2560Q-33GSP have a lower operating temperature maximum? A: RT2560Q-33GSP is qualified to AEC-Q100 automotive standards with a -40°C ~ 85°C operating range. Applications requiring operation above 85°C must use LP2951DR or LP2951CS-L-3-3/TR, which support -40°C ~ 125°C.

Q: Can RT2560Q-33GSP be used in applications requiring an Enable control feature? A: No. RT2560Q-33GSP does not include an Enable control feature. Applications requiring output enable/disable functionality must use LP2951DR or LP2951CS-L-3-3/TR.

Q: What are the packaging differences between these substitutes? A: All parts use 8-SOIC surface mount packages with identical 0.154" (3.90mm) width. RT2560Q-33GSP includes an exposed pad for enhanced thermal dissipation. Tape & Reel (TR) and Cut Tape (CT) packaging options affect supply chain logistics but not electrical or mechanical compatibility.

Q: Which substitute offers the best power efficiency? A: LP2951CS-L-3-3/TR provides the lowest dropout voltage (0.45V @ 100mA), reducing power dissipation in the regulator. RT2560Q-33GSP offers the lowest quiescent current (5 µA), minimizing standby power consumption. Selection depends on the specific application power profile.