LP2981AIM5-2.5 Equivalent & Substitute Parts

Part Overview

The LP2981AIM5-2.5 is a linear voltage regulator IC from Texas Instruments designed for positive fixed 2.5V output at 100mA in SOT-23-5 surface mount packaging. This part is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement. The device provides micropower regulation with integrated protection features including over-current, over-temperature, and short-circuit protection, suitable for low-power applications requiring stable 2.5V rails.

Substiute Parts

LP2981AIM5-2.5

Texas InstrumentsIn Stock: 9166LP2981AIM5-2.5 Datasheet

Current PartRFQ

LP2981IM5-2.5/NOPB

National SemiconductorIn Stock: 1817LP2981IM5-2.5/NOPB Datasheet

Parametric EquivalentRFQ

LD2981ABM50TR

STMicroelectronicsIn Stock: 57157LD2981ABM50TR Datasheet

MFR RecommendedRFQ

LD2981CM50TR

STMicroelectronicsIn Stock: 25237LD2981CM50TR Datasheet

MFR RecommendedRFQ

MIC5225-2.5YM5-TR

Microchip TechnologyIn Stock: 1032MIC5225-2.5YM5-TR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the LP2981AIM5-2.5 is determined by the following critical parameters:

• Output voltage: 2.5V fixed
• Output current capability: 100mA minimum
• Package: SOT-23-5 (SC-74A, SOT-753)
• Input voltage range: 16V maximum
• Operating temperature range: -40°C to 125°C
• Mounting type: Surface mount
• Control features: Enable function
• Protection: Over-current and over-temperature minimum

Substitute parts are grouped into two categories:

Parametric Equivalents maintain identical electrical specifications including 2.5V output and 100mA current rating.

Manufacturer Recommended Alternatives provide functional substitution with modified output voltage (5V) or enhanced current capability (150mA), suitable for applications where the primary constraint is the SOT-23-5 package form factor and general linear regulation topology rather than exact voltage matching.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Identical Specifications):

LP2981IM5-2.5/NOPB from National Semiconductor is the parametric equivalent, maintaining 2.5V output, 100mA current, and 0.37V dropout voltage. This part is active and suitable for direct substitution in existing designs. The part is available in bulk packaging.

MIC5225-2.5YM5-TR from Microchip Technology provides 2.5V output with enhanced 150mA current capability in the same SOT-23-5 package. This part is active and ROHS3 compliant, offering higher current headroom for applications approaching the 100mA limit. Dropout voltage is 0.45V at 150mA, slightly higher than the original specification.

For Voltage-Modified Substitution (5V Output):

LD2981ABM50TR and LD2981CM50TR from STMicroelectronics both provide 5V fixed output with 100mA current in SOT-23-5 packaging. These parts are active and ROHS3 compliant. Selection between these two variants depends on packaging requirements: LD2981ABM50TR is supplied in Cut Tape (CT) & Digi-Reel format, while LD2981CM50TR is supplied in Tape & Reel (TR) format. Both exhibit 0.375V dropout voltage and 150 µA quiescent current. These alternatives are suitable only for applications where 5V output is acceptable or where the design can be modified to accommodate the different voltage rail.

All substitute parts maintain the SOT-23-5 package form factor, enabling direct PCB footprint compatibility. Selection should prioritize active product status and compliance certifications for new designs.

Frequently Asked Questions (FAQ)

Q: Can LP2981IM5-2.5/NOPB replace LP2981AIM5-2.5 without circuit modification?

A: Yes. LP2981IM5-2.5/NOPB is a parametric equivalent with identical output voltage (2.5V), current rating (100mA), dropout voltage (0.37V @ 100mA), and quiescent current (95 µA). Both parts use SOT-23-5 packaging and support the same operating temperature range (-40°C to 125°C). No circuit modification is required.

Q: What is the difference between LD2981ABM50TR and LD2981CM50TR?

A: Both parts are functionally identical STMicroelectronics linear regulators with 5V output and 100mA current capability in SOT-23-5 packaging. The primary difference is packaging format: LD2981ABM50TR is supplied in Cut Tape (CT) & Digi-Reel format, while LD2981CM50TR is supplied in Tape & Reel (TR) format. Electrical specifications, including dropout voltage (0.375V @ 100mA) and quiescent current (150 µA), are identical.

Q: Can MIC5225-2.5YM5-TR be used as a direct replacement?

A: MIC5225-2.5YM5-TR maintains the 2.5V output voltage and SOT-23-5 package, enabling direct PCB footprint compatibility. However, this part provides 150mA output current versus the original 100mA specification, and exhibits 0.45V dropout voltage at 150mA compared to 0.37V @ 100mA for the original part. Use this part when higher current capability is beneficial or when the slightly higher dropout voltage is acceptable within the application's input voltage margin.

Q: Why do LD2981ABM50TR and LD2981CM50TR have 5V output instead of 2.5V?

A: These STMicroelectronics parts are manufacturer-recommended alternatives that prioritize package compatibility (SOT-23-5) and general linear regulation topology over exact voltage matching. They are suitable for applications where the design can accommodate 5V output or where the primary constraint is the surface-mount package form factor rather than the specific 2.5V voltage rail.

Q: Are all substitute parts RoHS compliant?

A: LP2981IM5-2.5/NOPB compliance status is not specified in available data. LD2981ABM50TR, LD2981CM50TR, and MIC5225-2.5YM5-TR are all ROHS3 compliant. The original LP2981AIM5-2.5 is RoHS non-compliant. For applications requiring RoHS compliance, select from the STMicroelectronics or Microchip alternatives.

Q: What is the inventory status of these substitute parts?

A: LP2981IM5-2.5/NOPB has 1806 pieces in stock. LD2981ABM50TR has 57080 pieces in stock. LD2981CM50TR has 25200 pieces in stock. MIC5225-2.5YM5-TR has 990 pieces in stock. Availability should be confirmed with the supplier for production quantities.