LP2951-30DR Equivalent & Substitute Parts

Part Overview

The LP2951-30DR 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 new production runs or design revisions.

Substiute Parts

LP2951-30DR

Texas InstrumentsIn Stock: 25480LP2951-30DR 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 LP2951-30DR is determined by the following critical parameters:

Primary Compatibility Criteria:

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

Secondary Compatibility Criteria:

• Voltage Dropout: 0.6V @ 100mA or lower
• RoHS Compliance: ROHS3 or equivalent
• MSL Rating: 1 (Unlimited) or equivalent

The LP2951-30DR accepts adjustable or fixed output voltage configurations. Substitute parts may be fixed-output variants (such as 3.3V fixed) provided they meet the electrical and mechanical requirements above.

Parameter Comparison

Engineering Selection Recommendations

LP2951DR (Texas Instruments) — Recommended Primary Substitute

The LP2951DR is the direct successor to the LP2951-30DR from the same manufacturer. It maintains identical electrical specifications (30V input maximum, 100mA output, 0.6V dropout, 120 µA quiescent current) and package configuration. Product status is Active with higher inventory availability (55,100 pcs). This part provides the highest design compatibility with minimal qualification effort. The adjustable/fixed output configuration matches the original part's flexibility.

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

This part is a fixed 3.3V output variant meeting all primary compatibility criteria: 8-SOIC package, 100mA output, 30V input maximum, -40°C ~ 125°C operating range, and ROHS3 compliance. The 0.45V dropout at 100mA is superior to the original specification. Product status is Active. Selection of this part requires design confirmation that a fixed 3.3V output meets application requirements. Higher quiescent current (170 µA vs. 120 µA) should be evaluated for battery-powered applications.

RT2560Q-33GSP (Richtek USA Inc.) — Specialized Substitute

This part is a fixed 3.3V output variant with automotive qualification (AEC-Q100) and superior quiescent current performance (5 µA). Input voltage rating extends to 36V. Operating temperature range is limited to -40°C ~ 85°C, which may not satisfy designs requiring full -40°C ~ 125°C operation. MSL rating is 3 (168 Hours) versus the original MSL 1. Selection requires confirmation of temperature range compatibility and automotive-grade requirement justification. Exposed pad design provides improved thermal performance.

Frequently Asked Questions (FAQ)

Q: Can LP2951DR be used as a direct replacement for LP2951-30DR?

A: Yes. The LP2951DR is electrically and mechanically compatible. Both parts share identical input/output voltage ratings (30V max input, 1.235V–30V output), 100mA current capability, 0.6V dropout specification, and 8-SOIC package footprint. The primary difference is product status: LP2951-30DR is Last Time Buy while LP2951DR is Active production.

Q: What is the difference between adjustable and fixed output variants?

A: The LP2951-30DR supports adjustable output voltage configuration via external resistor networks, allowing output voltage selection between 1.235V and 30V. Fixed-output variants (LP2951CS-L-3-3/TR and RT2560Q-33GSP) are factory-configured to 3.3V output. If your design requires adjustable output capability, only LP2951DR maintains this flexibility. If your application uses fixed 3.3V output, fixed variants are acceptable.

Q: Are the fixed 3.3V variants compatible with designs using adjustable output?

A: Only if the design's required output voltage is 3.3V. Fixed-output parts cannot be adjusted to other voltages. Review your schematic to confirm the intended output voltage setting. If external resistor dividers are present for voltage adjustment, the fixed variants are not suitable.

Q: What is the significance of the 8-SOIC package with exposed pad on RT2560Q-33GSP?

A: The exposed pad provides direct thermal connection to the PCB, improving heat dissipation compared to standard 8-SOIC packages without exposed pads. This is beneficial for applications operating at maximum current (100mA) or elevated ambient temperatures. Footprint compatibility remains maintained with standard 8-SOIC layouts, though the exposed pad should be connected to ground for optimal thermal performance.

Q: Does operating temperature range affect substitution eligibility?

A: Yes. The LP2951-30DR operates from -40°C to 125°C. LP2951DR and LP2951CS-L-3-3/TR maintain this range. RT2560Q-33GSP is limited to -40°C to 85°C. If your application requires operation above 85°C, RT2560Q-33GSP is not suitable. Confirm your design's maximum operating temperature requirement before selection.

Q: What is the MSL (Moisture Sensitivity Level) impact?

A: LP2951-30DR, LP2951DR, and LP2951CS-L-3-3/TR are rated MSL 1 (Unlimited), meaning no moisture bake-out is required before soldering. RT2560Q-33GSP is rated MSL 3 (168 Hours), requiring moisture bake-out within 168 hours of package opening. For high-volume production with extended component storage, MSL 1 parts reduce handling complexity.

Q: Can I use RT2560Q-33GSP in a design originally specified for LP2951-30DR?

A: Only if three conditions are met: (1) your design requires fixed 3.3V output, (2) maximum operating temperature does not exceed 85°C, and (3) automotive-grade qualification is acceptable or required. The superior quiescent current (5 µA vs. 120 µA) and higher input voltage rating (36V vs. 30V) are advantages. The reduced temperature range and MSL 3 rating are limitations requiring design review.