LP2981-29DBVR Equivalent & Substitute Parts

Part Overview

The LP2981-29DBVR is a linear voltage regulator IC from Texas Instruments, classified as a Power Management (PMIC) device. It delivers a fixed positive output of 2.9V at 100mA in a surface-mount SOT-23-5 package. The device is currently obsolete, making identification of equivalent and substitute parts essential for ongoing system support, design updates, and procurement continuity.

Substiute Parts

LP2981-29DBVR

Texas InstrumentsIn Stock: 4042LP2981-29DBVR Datasheet

Current PartRFQ

TPS7A2401DBVR

Texas InstrumentsIn Stock: 19846TPS7A2401DBVR Datasheet

MFR RecommendedRFQ

LP2981A-29DBVR

Texas InstrumentsIn Stock: 3802LP2981A-29DBVR Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the LP2981-29DBVR are classified based on the following substitution criteria:

Parametric Equivalent: Parts that maintain identical electrical specifications (fixed 2.9V output, 100mA current rating, same package) and can serve as direct replacements without circuit modification.

Manufacturer Recommended Substitute: Parts that offer enhanced performance characteristics (higher current capability, adjustable output, improved quiescent current) while maintaining compatibility with the same physical package and operating temperature range. These parts may require circuit design consideration but provide functional equivalence.

Key parameters determining substitution validity:

• Output voltage configuration (Fixed vs. Adjustable)
• Maximum output current rating
• Package type (SOT-23-5)
• Operating temperature range (-40°C ~ 125°C)
• Input voltage maximum rating
• Dropout voltage performance

Parameter Comparison

Engineering Selection Recommendations

LP2981A-29DBVR (Parametric Equivalent): This part provides identical electrical and mechanical specifications to the LP2981-29DBVR. Both devices are obsolete, but the LP2981A-29DBVR maintains the same fixed 2.9V output, 100mA current rating, and SOT-23-5 package. Selection between these two obsolete variants depends on inventory availability and procurement lead times. Both are ROHS3 compliant with MSL 1 rating.

TPS7A2401DBVR (Manufacturer Recommended Substitute): This part is actively manufactured by Texas Instruments and represents the recommended upgrade path from the obsolete LP2981-29DBVR. While the TPS7A2401DBVR features adjustable output voltage (1.24V - 17.75V) rather than fixed 2.9V, it can be configured to deliver 2.9V through external resistor networks. The device offers superior performance: 200mA output current (versus 100mA), lower dropout voltage (0.25V @ 200mA versus 0.37V @ 100mA), and significantly lower quiescent current (4.5 µA versus 95 µA). The TPS7A2401DBVR maintains the same SOT-23-5 package and operating temperature range, ensuring mechanical and thermal compatibility. Active product status ensures long-term availability and support.

Frequently Asked Questions (FAQ)

Q: Can LP2981A-29DBVR directly replace LP2981-29DBVR without circuit modification?

A: Yes. The LP2981A-29DBVR is a parametric equivalent with identical electrical specifications (2.9V fixed output, 100mA current, 0.37V dropout voltage) and the same SOT-23-5 package. No circuit changes are required.

Q: Why is TPS7A2401DBVR recommended if it has adjustable output instead of fixed 2.9V?

A: The TPS7A2401DBVR can be externally configured to deliver a fixed 2.9V output through resistor divider networks on the feedback pin. This flexibility, combined with active product status, superior performance metrics (lower quiescent current, higher current capability, lower dropout voltage), and long-term availability, makes it the preferred upgrade path from the obsolete LP2981-29DBVR.

Q: Are all three parts compatible with the same PCB footprint?

A: Yes. All three parts use the SC-74A/SOT-753 package (SOT-23-5), ensuring identical pin configuration and PCB footprint compatibility.

Q: What is the impact of using TPS7A2401DBVR's lower quiescent current (4.5 µA vs. 95 µA)?

A: The TPS7A2401DBVR draws significantly less standby current, reducing overall system power consumption. This is particularly beneficial in battery-powered or low-power applications.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. LP2981-29DBVR, LP2981A-29DBVR, and TPS7A2401DBVR are all ROHS3 compliant with MSL 1 (Unlimited) moisture sensitivity rating.

Q: What is the primary limitation when selecting between the obsolete variants?

A: Both LP2981-29DBVR and LP2981A-29DBVR are obsolete. Selection depends on current inventory availability and procurement lead times. For new designs or long-term support, TPS7A2401DBVR is the recommended choice due to active manufacturing status.