LP5951MF-2.5 Linear Voltage Regulator IC Equivalent & Substitute Parts

Part Overview

The LP5951MF-2.5 is a linear voltage regulator IC from Texas Instruments designed for positive fixed 2.5V output applications with 150mA current capacity in SOT-23-5 surface mount packaging. This part is classified as obsolete, making equivalent and substitute parts necessary for new designs and production continuity. The device provides regulated power management with integrated protection features including overcurrent, over-temperature, and short-circuit protection, suitable for applications requiring stable 2.5V rails with moderate current demands.

Key Parameters

Parameter	Value
Output Voltage (Fixed)	2.5V
Output Current	150mA
Input Voltage (Max)	5.5V
Voltage Dropout (Max)	0.35V @ 150mA
Quiescent Current (Iq)	55 µA
Package Type	SOT-23-5 (SC-74A)
Output Configuration	Positive Fixed
Operating Temperature	-40°C ~ 125°C
Protection Features	Overcurrent, Over-Temperature, Short Circuit

Substitute Part Grouping Explanation

Substitution for the LP5951MF-2.5 is determined by the following critical parameters:

Fixed output voltage of 2.5V
Output current capability of 150mA or greater
Maximum input voltage of 5.5V or higher
SOT-23-5 package compatibility
Positive output configuration
Enable control feature
Operating temperature range of -40°C to 85°C minimum

Parts are grouped into three categories: parametric equivalents (identical electrical specifications with different packaging or compliance status), manufacturer-recommended alternatives (enhanced performance characteristics), and functional substitutes (higher current capacity or improved dropout voltage).

Parameter Comparison

Part Number	Manufacturer	Output Voltage	Output Current	Dropout Voltage	Iq (µA)	Package	Status	RoHS
LP5951MF-2.5	Texas Instruments	2.5V	150mA	0.35V @ 150mA	55	SOT-23-5	Obsolete	Non-compliant
LP5951MF-2.5/NOPB	Texas Instruments	2.5V	150mA	0.35V @ 150mA	55	SOT-23-5	Active	ROHS3 Compliant
LP5951MFX-2.5/NOPB	Texas Instruments	2.5V	150mA	0.35V @ 150mA	55	SOT-23-5	Active	ROHS3 Compliant
BU25SD2MG-MTR	Rohm Semiconductor	2.5V	200mA	0.18V @ 100mA	80	5-SSOP	Active	ROHS3 Compliant
MIC5306-2.5YD5-TR	Microchip Technology	2.5V	150mA	0.2V @ 150mA	25	TSOT-23-5	Active	ROHS3 Compliant
S-1135D25-M5T1U	ABLIC Inc.	2.5V	300mA	Not specified	1	SOT-23-5	Obsolete	ROHS3 Compliant
S-1312A25-M5T1U3	ABLIC Inc.	2.5V	150mA	0.32V @ 100mA	30	SOT-23-5	Active	ROHS3 Compliant
S-1312B25-M5T1U3	ABLIC Inc.	2.5V	150mA	0.32V @ 100mA	30	SOT-23-5	Active	ROHS3 Compliant
S-1312C25-M5T1U3	ABLIC Inc.	2.5V	150mA	0.32V @ 100mA	30	SOT-23-5	Active	ROHS3 Compliant
S-1312D25-M5T1U3	ABLIC Inc.	2.5V	150mA	0.32V @ 100mA	30	SOT-23-5	Active	ROHS3 Compliant
S-1313A25-M5T1U3	ABLIC Inc.	2.5V	200mA	0.38V @ 100mA	1.35	SOT-23-5	Active	ROHS3 Compliant

Engineering Selection Recommendations

Parametric Equivalents (Direct Replacement): LP5951MF-2.5/NOPB and LP5951MFX-2.5/NOPB are direct parametric equivalents with identical electrical specifications. Both are active products with ROHS3 compliance, addressing the obsolescence of the original LP5951MF-2.5. Selection between these two depends on packaging requirements: LP5951MF-2.5/NOPB is available in Cut Tape and Digi-Reel formats, while LP5951MFX-2.5/NOPB is supplied in Tape & Reel format with higher inventory availability (17,930 units).

Manufacturer-Recommended Alternatives: ABLIC S-1312 series (S-1312A25-M5T1U3, S-1312B25-M5T1U3, S-1312C25-M5T1U3, S-1312D25-M5T1U3) provides identical 150mA output current with improved quiescent current (30 µA versus 55 µA) and lower dropout voltage (0.32V @ 100mA versus 0.35V @ 150mA). All variants are active products with ROHS3 compliance and SOT-23-5 packaging. These parts are suitable for applications where lower power consumption is beneficial.

Microchip MIC5306-2.5YD5-TR matches the 150mA output specification with superior quiescent current performance (25 µA) and lower dropout voltage (0.2V @ 150mA). The TSOT-23-5 package is mechanically compatible with SOT-23-5 footprints. This part is active and ROHS3 compliant.

Higher Current Capacity Alternatives: BU25SD2MG-MTR (Rohm Semiconductor) and S-1313A25-M5T1U3 (ABLIC) provide 200mA output current, exceeding the original 150mA specification. BU25SD2MG-MTR features superior dropout voltage (0.18V @ 100mA) and is qualified for automotive applications (AEC-Q100). S-1313A25-M5T1U3 offers ultra-low quiescent current (1.35 µA). Both are active and ROHS3 compliant.

S-1135D25-M5T1U (ABLIC) provides 300mA output current with exceptional quiescent current (1 µA), though it is classified as obsolete. This part is suitable only for legacy design maintenance.

Frequently Asked Questions (FAQ)

Q: Can I use LP5951MF-2.5/NOPB as a direct replacement for LP5951MF-2.5? A: Yes. LP5951MF-2.5/NOPB is a parametric equivalent with identical electrical specifications. The primary difference is product status (active versus obsolete) and RoHS compliance (ROHS3 compliant versus non-compliant). Packaging options differ: the /NOPB variant is available in Cut Tape and Digi-Reel formats.

Q: What is the difference between LP5951MF-2.5/NOPB and LP5951MFX-2.5/NOPB? A: Both are parametric equivalents with identical electrical performance. The difference is packaging format: LP5951MF-2.5/NOPB is supplied in Cut Tape and Digi-Reel, while LP5951MFX-2.5/NOPB is supplied in Tape & Reel format. LP5951MFX-2.5/NOPB has significantly higher inventory availability (17,930 units versus 3,772 units).

Q: Are ABLIC S-1312 series parts compatible with the original LP5951MF-2.5 footprint? A: Yes. All S-1312 variants use SOT-23-5 packaging, which is mechanically and electrically compatible with the original part's SC-74A/SOT-753 package designation. These parts offer improved performance characteristics including lower quiescent current and dropout voltage.

Q: Can I substitute the LP5951MF-2.5 with a higher current part like BU25SD2MG-MTR or S-1313A25-M5T1U3? A: Yes, provided your application does not have current limitations that would be violated by the higher output capability. Both parts maintain the 2.5V output voltage and SOT-23-5 package compatibility. BU25SD2MG-MTR includes automotive qualification (AEC-Q100). Verify that the higher quiescent current (80 µA for BU25SD2MG-MTR) does not impact your power budget.

Q: What is the difference between SOT-23-5 and TSOT-23-5 packages? A: TSOT-23-5 is a thin variant of SOT-23-5 with reduced height. Both packages are mechanically compatible on standard PCB footprints. Microchip MIC5306-2.5YD5-TR uses TSOT-23-5 packaging and is suitable for applications requiring lower profile components.

Q: Which substitute part has the lowest quiescent current? A: S-1135D25-M5T1U and S-1313A25-M5T1U3 both feature ultra-low quiescent current (1 µA and 1.35 µA respectively), compared to 55 µA for the original LP5951MF-2.5. These parts are optimal for battery-powered or low-power standby applications.

Q: Are all substitute parts RoHS compliant? A: All active substitute parts listed are ROHS3 compliant. The original LP5951MF-2.5 is RoHS non-compliant. S-1135D25-M5T1U is obsolete but ROHS3 compliant.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message