LP2951ACSDX-3.3 Linear Voltage Regulator IC Equivalent & Substitute Parts

Part Overview

The LP2951ACSDX-3.3 is a linear voltage regulator IC from Texas Instruments designed for positive adjustable (fixed) output applications. This Surface Mount device delivers 100mA output current in an 8-WSON (4x4) package with integrated protection features including over-current, over-temperature, and short-circuit protection. The part is currently listed as obsolete, making equivalent substitute parts necessary for ongoing production and maintenance applications. Active alternatives with identical electrical and mechanical specifications are available from the same manufacturer.

Substiute Parts

LP2951ACSDX-3.3

Texas InstrumentsIn Stock: 52223LP2951ACSDX-3.3 Datasheet

Current PartRFQ

LP2951ACSDX-3.3/NOPB

Texas InstrumentsIn Stock: 1032LP2951ACSDX-3.3/NOPB Datasheet

Parametric EquivalentRFQ

LP2951CSD-3.3/NOPB

Texas InstrumentsIn Stock: 18364LP2951CSD-3.3/NOPB Datasheet

Parametric EquivalentRFQ

LP2951CSDX-3.3/NOPB

Texas InstrumentsIn Stock: 4916LP2951CSDX-3.3/NOPB Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LP2951ACSDX-3.3 is determined by strict equivalence across the following critical parameters:

• Output Configuration: Positive
• Output Type: Adjustable (Fixed)
• Voltage specifications: Input (Max) 30V, Output (Min/Fixed) 1.235V (3.3V), Output (Max) 29V
• Current rating: 100mA output, 120 µA quiescent
• Voltage Dropout: 0.6V @ 100mA
• Protection Features: Over Current, Over Temperature, Short Circuit
• Package: 8-WSON (4x4) with exposed pad
• Operating Temperature: -40°C ~ 125°C (TJ)

All substitute parts listed maintain identical electrical performance and mechanical compatibility. Differences exist only in product status (active vs. obsolete) and RoHS compliance certification.

Parameter Comparison

Engineering Selection Recommendations

The LP2951ACSDX-3.3 is obsolete and should be replaced with one of the three active alternatives: LP2951ACSDX-3.3/NOPB, LP2951CSD-3.3/NOPB, or LP2951CSDX-3.3/NOPB. All three substitutes provide identical electrical and mechanical performance while offering active product status and ROHS3 compliance.

Selection between the three active alternatives depends on packaging requirements and inventory availability:

LP2951ACSDX-3.3/NOPB is the direct equivalent with 1,011 pieces in stock and Tape & Reel packaging.

LP2951CSD-3.3/NOPB offers the highest inventory availability at 18,300 pieces in stock with Tape & Reel packaging.

LP2951CSDX-3.3/NOPB provides an intermediate inventory option with 4,900 pieces in stock and Tape & Reel packaging.

All three parts are ROHS3 compliant and REACH unaffected, meeting modern regulatory requirements. The choice between them should be based on procurement lead time, packaging format compatibility with assembly equipment, and inventory requirements for production volume.

Frequently Asked Questions (FAQ)

Q: Can LP2951ACSDX-3.3/NOPB be used as a direct replacement for LP2951ACSDX-3.3?

A: Yes. Both parts are electrically and mechanically identical. The primary difference is that LP2951ACSDX-3.3/NOPB is active and ROHS3 compliant, while the original is obsolete and RoHS non-compliant. The /NOPB suffix indicates lead-free solder ball material.

Q: What is the difference between LP2951CSD-3.3/NOPB and LP2951CSDX-3.3/NOPB?

A: Both parts are electrically identical with the same voltage, current, and thermal specifications. The difference lies in the device marking code (CSD vs. CSDX), which reflects internal manufacturing variations. Both are functionally equivalent for circuit design purposes.

Q: Are all substitute parts available in the same 8-WSON (4x4) package?

A: Yes. All substitute parts use the 8-WDFN Exposed Pad package with 8-WSON (4x4) supplier device package designation. PCB footprints and assembly processes remain unchanged.

Q: What is the significance of the /NOPB designation?

A: The /NOPB suffix indicates the part uses lead-free solder ball material and is RoHS compliant. This is a manufacturing and environmental compliance designation with no impact on electrical performance.

Q: Can I mix different substitute part numbers in the same production batch?

A: Yes. All three active substitutes are parametrically equivalent and can be used interchangeably. However, for traceability and quality control purposes, maintaining consistent part numbers within a single production lot is recommended.

Q: What is the operating temperature range for all substitute parts?

A: All parts operate from -40°C to 125°C junction temperature (TJ), providing identical thermal performance across the full range.

Q: Are there any differences in protection features between the main part and substitutes?

A: No. All parts include identical protection features: over-current, over-temperature, and short-circuit protection.