LP3964EMPX-3.3 Linear Voltage Regulator IC — Equivalent & Substitute Parts

Part Overview

The LP3964EMPX-3.3 is a linear voltage regulator IC from Texas Instruments, classified as a Power Management (PMIC) component. This device delivers a fixed 3.3V output at 800mA in a surface-mount SOT-223-5 package. The main part is currently listed as obsolete, making equivalent substitute parts necessary for ongoing design support and procurement.

Key Parameters

Parameter	Value
Manufacturer	Texas Instruments
Output Voltage (Fixed)	3.3V
Output Current	800mA
Input Voltage (Max)	7V
Voltage Dropout (Max)	0.35V @ 800mA
Package Type	SOT-223-5
Output Configuration	Positive Fixed
Protection Features	Over Current, Over Temperature, Short Circuit
Operating Temperature Range	-40°C to 125°C
RoHS Status	ROHS3 Compliant

Substitute Part Grouping Explanation

Substitute parts for the LP3964EMPX-3.3 are selected based on strict electrical and mechanical parameter matching:

Critical Matching Parameters:

Fixed output voltage: 3.3V
Output current capability: 800mA
Maximum input voltage: 7V
Voltage dropout: 0.35V @ 800mA
Package: SOT-223-5 (TO-261-5, TO-261AB)
Output configuration: Positive Fixed
Protection features: Over Current, Over Temperature, Short Circuit
Operating temperature: -40°C to 125°C
RoHS3 compliance and MSL Level 1

All substitute parts listed below meet these electrical and mechanical requirements and are manufactured by Texas Instruments. Substitutes differ only in product status (active vs. obsolete), quiescent current specifications, PSRR ratings where specified, and packaging format (Tape & Reel vs. Cut Tape).

Parameter Comparison

Part Number	Manufacturer	Product Status	Output Voltage	Output Current	Input Voltage (Max)	Dropout Voltage	Quiescent Current	Package	Packaging Format
LP3964EMPX-3.3	Texas Instruments	Obsolete	3.3V	800mA	7V	0.35V @ 800mA	9 mA	SOT-223-5	Not specified
LP3871EMP-3.3/NOPB	Texas Instruments	Active	3.3V	800mA	7V	0.35V @ 800mA	5 mA	SOT-223-5	Tape & Reel (TR)
LP3871EMPX-3.3/NOPB	Texas Instruments	Active	3.3V	800mA	7V	0.35V @ 800mA	5 mA	SOT-223-5	Tape & Reel (TR)
LP3874EMP-3.3/NOPB	Texas Instruments	Active	3.3V	800mA	7V	0.35V @ 800mA	9 mA	SOT-223-5	Cut Tape (CT) & Digi-Reel®
LP3874EMPX-3.3/NOPB	Texas Instruments	Active	3.3V	800mA	7V	0.35V @ 800mA	9 mA	SOT-223-5	Tape & Reel (TR)
LP3961EMP-3.3/NOPB	Texas Instruments	Active	3.3V	800mA	7V	0.35V @ 800mA	9 mA	SOT-223-5	Cut Tape (CT) & Digi-Reel®
LP3964EMP-3.3/NOPB	Texas Instruments	Active	3.3V	800mA	7V	0.35V @ 800mA	9 mA	SOT-223-5	Cut Tape (CT) & Digi-Reel®

Engineering Selection Recommendations

Primary Recommendation: LP3964EMP-3.3/NOPB or LP3874EMP-3.3/NOPB

Both parts are active products with full Texas Instruments support, ROHS3 compliance, and identical electrical specifications to the obsolete LP3964EMPX-3.3. These parts maintain the same quiescent current (9 mA) and dropout voltage characteristics. LP3964EMP-3.3/NOPB provides direct base model continuity, while LP3874EMP-3.3/NOPB offers equivalent performance with established supply availability.

Alternative Recommendation: LP3871EMP-3.3/NOPB or LP3871EMPX-3.3/NOPB

These active alternatives feature reduced quiescent current (5 mA vs. 9 mA), providing improved power efficiency in battery-powered or low-power applications. Both maintain identical output voltage, current, and dropout specifications. The LP3871 series is suitable when lower standby current consumption is a design priority.

Packaging Considerations: All substitute parts use SOT-223-5 packaging and are mechanically compatible with the original design. Selection between Tape & Reel and Cut Tape formats depends on procurement volume and assembly requirements.

Frequently Asked Questions (FAQ)

Q: Can LP3871EMP-3.3/NOPB replace LP3964EMPX-3.3 directly?

A: Yes. Both deliver 3.3V at 800mA with identical dropout voltage and protection features. The LP3871 has lower quiescent current (5 mA vs. 9 mA), which reduces power consumption without affecting output performance. No circuit modifications are required.

Q: What is the difference between LP3874EMP-3.3/NOPB and LP3874EMPX-3.3/NOPB?

A: Both are active LP3874 variants with identical electrical specifications. The difference is packaging format: LP3874EMP-3.3/NOPB is supplied in Cut Tape & Digi-Reel format, while LP3874EMPX-3.3/NOPB is supplied in Tape & Reel format. Electrical performance is equivalent.

Q: Why is the original LP3964EMPX-3.3 listed as obsolete?

A: Product obsolescence is determined by the manufacturer. Active equivalents (LP3964EMP-3.3/NOPB, LP3874EMP-3.3/NOPB, LP3871EMP-3.3/NOPB) provide continued design support and supply availability.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All listed substitute parts carry ROHS3 compliance and MSL Level 1 (Unlimited moisture sensitivity), matching the original part's environmental certifications.

Q: Does quiescent current affect circuit compatibility?

A: Quiescent current affects standby power consumption but does not impact output voltage regulation or load current capability. The LP3871 series (5 mA Iq) consumes less standby power than LP3874/LP3961/LP3964 variants (9 mA Iq). Selection depends on application power budget requirements.

Q: Can I mix packaging formats in production?

A: Yes, provided your assembly process supports both Tape & Reel and Cut Tape formats. All substitute parts use identical SOT-223-5 package geometry and are mechanically interchangeable on the PCB.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message