LP2981IM5X-3.3 Equivalent & Substitute Parts

Part Overview

The LP2981IM5X-3.3 is a linear voltage regulator IC from Texas Instruments designed for positive fixed 3.3V output at 100mA in SOT-23-5 surface mount packaging. This part is classified as obsolete, which necessitates identification of active equivalent and substitute components for new designs and ongoing production requirements. The LP2981 series provides regulated power management with integrated protection features including over-current, over-temperature, and short-circuit protection, making it suitable for low-power applications requiring stable 3.3V rails.

Key Parameters

Parameter	Value
Output Voltage (Fixed)	3.3V
Output Current	100mA
Input Voltage (Max)	16V
Dropout Voltage (Max)	0.37V @ 100mA
Quiescent Current	95 µA
PSRR	63dB (1kHz)
Package	SOT-23-5 (SC-74A)
Protection Features	Over Current, Over Temperature, Short Circuit
Operating Temperature Range	-40°C to 125°C
Control Features	Enable

Substitute Part Grouping Explanation

Substitution eligibility for the LP2981IM5X-3.3 is determined by the following critical parameters:

Output voltage fixed at 3.3V
Output current capability of 100mA minimum
Input voltage tolerance up to 16V
SOT-23-5 package compatibility
Dropout voltage performance at rated current
Quiescent current specifications
Protection feature set (Over Current, Over Temperature, Short Circuit)
Operating temperature range -40°C to 125°C

All Texas Instruments LP2981 and LP2981A variants listed below meet these electrical and mechanical requirements. The LD2980ABM33TR from STMicroelectronics is included as a manufacturer-recommended alternative, though it operates at reduced output current (50mA vs 100mA) and should be evaluated for application-specific current requirements.

Parameter Comparison

Part Number	Manufacturer	Output Current	Dropout Voltage	Quiescent Current	Product Status	RoHS Compliance	Inventory (Pcs)
LP2981IM5X-3.3	Texas Instruments	100mA	0.37V @ 100mA	95 µA	Obsolete	Non-compliant	6400
LP2981-33DBVR	Texas Instruments	100mA	0.37V @ 100mA	95 µA	Active	ROHS3 Compliant	69150
LP2981-33DBVT	Texas Instruments	100mA	0.37V @ 100mA	95 µA	Last Time Buy	ROHS3 Compliant	4490
LP2981A-33DBVR	Texas Instruments	100mA	0.37V @ 100mA	95 µA	Active	ROHS3 Compliant	56100
LP2981A-33DBVT	Texas Instruments	100mA	0.37V @ 100mA	95 µA	Last Time Buy	ROHS3 Compliant	1900
LP2981A-33DBVTG4	Texas Instruments	100mA	0.37V @ 100mA	95 µA	Discontinued at DiGi Electronics	ROHS3 Compliant	23637
LP2981AIM5-3.3/NOPB	Texas Instruments	100mA	0.37V @ 100mA	95 µA	Active	ROHS3 Compliant	4948
LP2981AIM5X-3.3/NOPB	Texas Instruments	100mA	0.37V @ 100mA	95 µA	Active	ROHS3 Compliant	7272
LP2981IM5-3.3/NOPB	Texas Instruments	100mA	0.37V @ 100mA	95 µA	Active	ROHS3 Compliant	18400
LP2981IM5X-3.3/NOPB	Texas Instruments	100mA	0.37V @ 100mA	95 µA	Active	ROHS3 Compliant	12302
LD2980ABM33TR	STMicroelectronics	50mA	0.225V @ 50mA	150 µA	Active	ROHS3 Compliant	29400

Engineering Selection Recommendations

For direct replacement of the obsolete LP2981IM5X-3.3, prioritize active Texas Instruments variants with ROHS3 compliance. The LP2981IM5X-3.3/NOPB and LP2981IM5-3.3/NOPB offer identical electrical specifications and are currently in active production status with substantial inventory availability. These parts maintain full parametric equivalence including 100mA output current, 0.37V dropout voltage, and complete protection feature sets.

The LP2981A-33DBVR represents an alternative with the highest inventory level (56,100 pcs) and active status, suitable for applications where packaging format flexibility is acceptable. Parts designated as "Last Time Buy" (LP2981-33DBVT and LP2981A-33DBVT) remain available but represent end-of-life inventory and should be considered only when immediate availability is critical.

The LD2980ABM33TR from STMicroelectronics is a manufacturer-recommended alternative but operates at reduced output current (50mA vs 100mA). This part is suitable only for applications with maximum current requirements not exceeding 50mA and should not be used as a direct replacement for designs requiring the full 100mA capability.

Frequently Asked Questions (FAQ)

Q: Can LP2981IM5X-3.3/NOPB directly replace LP2981IM5X-3.3?

A: Yes. The LP2981IM5X-3.3/NOPB is a direct parametric equivalent with identical electrical specifications: 3.3V fixed output, 100mA output current, 0.37V dropout voltage at rated current, and SOT-23-5 packaging. The primary difference is product status (Active vs Obsolete) and RoHS compliance (ROHS3 Compliant vs Non-compliant).

Q: What is the difference between LP2981 and LP2981A variants?

A: Both LP2981 and LP2981A variants share identical electrical parameters for the 3.3V 100mA configuration. The distinction lies in product lifecycle status and packaging designations. The "A" suffix typically indicates a revised version, but electrical performance remains equivalent for this output voltage and current rating.

Q: Can LD2980ABM33TR be used as a substitute?

A: The LD2980ABM33TR is electrically compatible for 3.3V output but operates at reduced output current (50mA maximum vs 100mA). Use this part only if your application current requirement does not exceed 50mA. For designs requiring 100mA capability, select Texas Instruments LP2981 or LP2981A variants.

Q: What do the packaging suffixes mean (DBVR, DBVT, IM5X, IM5)?

A: These suffixes indicate packaging and tape format specifications. DBVR and DBVT denote different tape configurations (Digi-Reel vs standard tape). IM5X and IM5 indicate specific lead frame and packaging variants. All variants maintain SOT-23-5 physical compatibility and identical electrical performance for the 3.3V 100mA rating.

Q: Are all listed substitutes RoHS compliant?

A: All Texas Instruments LP2981 and LP2981A variants listed are ROHS3 Compliant. The original LP2981IM5X-3.3 is RoHS non-compliant. The LD2980ABM33TR from STMicroelectronics is ROHS3 Compliant.

Q: Which substitute has the best availability?

A: LP2981-33DBVR offers the highest inventory level at 69,150 pcs in active production status, followed by LP2981A-33DBVR at 56,100 pcs. Both are suitable for immediate procurement.

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