LP3961ESX-3.3 Linear Voltage Regulator Equivalent & Substitute Parts

Part Overview

The LP3961ESX-3.3 is a linear voltage regulator IC from Texas Instruments designed for positive fixed 3.3V output applications with 800mA current capacity in a TO-263 (DDPAK-5) surface mount package. This part is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement continuity. The device provides regulated 3.3V output with integrated protection features including over-current, over-temperature, and short-circuit protection, suitable for applications requiring stable low-voltage power distribution.

Substiute Parts

LP3961ESX-3.3

Texas InstrumentsIn Stock: 2083LP3961ESX-3.3 Datasheet

Current PartRFQ

LP3961ESX-3.3/NOPB

Texas InstrumentsIn Stock: 5145LP3961ESX-3.3/NOPB Datasheet

DirectRFQ

LP3871ESX-3.3/NOPB

Texas InstrumentsIn Stock: 1674LP3871ESX-3.3/NOPB Datasheet

Parametric EquivalentRFQ

LP3964ESX-3.3/NOPB

Texas InstrumentsIn Stock: 2293LP3964ESX-3.3/NOPB Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the LP3961ESX-3.3 are classified based on electrical and mechanical parameter compatibility:

Direct Manufacturer Substitute: LP3961ESX-3.3/NOPB is the direct equivalent with identical electrical specifications and packaging. This part differs only in product status (Active vs. Obsolete) and RoHS compliance level (ROHS3 Compliant vs. non-compliant), making it the primary replacement option.

Parametric Equivalents: LP3871ESX-3.3/NOPB and LP3964ESX-3.3/NOPB are parametric equivalents that maintain all critical electrical parameters including output voltage (3.3V), output current (800mA), input voltage maximum (7V), voltage dropout (0.35V @ 800mA), package type (TO-263 DDPAK-5), operating temperature range (-40°C to 125°C), and protection features (Over Current, Over Temperature, Short Circuit).

Key Parameters Determining Substitution:

• Output voltage: 3.3V fixed
• Output current capacity: 800mA
• Package/Case: TO-263-6, D2PAK (5 Leads + Tab)
• Mounting type: Surface Mount
• Protection features: Over Current, Over Temperature, Short Circuit
• Operating temperature range: -40°C to 125°C

Parameter Comparison

Engineering Selection Recommendations

Primary Selection: LP3961ESX-3.3/NOPB is the recommended direct substitute for the obsolete LP3961ESX-3.3. This part maintains identical electrical and mechanical specifications while offering Active product status and ROHS3 compliance, ensuring long-term availability and regulatory alignment.

Alternative Selections: LP3871ESX-3.3/NOPB and LP3964ESX-3.3/NOPB are valid parametric equivalents for applications where the primary substitute is unavailable. Both parts maintain all critical electrical parameters and package compatibility. LP3871ESX-3.3/NOPB features reduced quiescent current (5mA vs. 9mA), which may provide power efficiency benefits in low-power applications. All substitute parts carry Active product status and ROHS3 compliance certification.

Compliance Considerations: All substitute parts are ROHS3 compliant and REACH unaffected, meeting current regulatory requirements for electronic component procurement. The original LP3961ESX-3.3 is RoHS non-compliant and should be replaced in new designs or production runs subject to RoHS directives.

Frequently Asked Questions (FAQ)

Q: Can LP3961ESX-3.3/NOPB be used as a direct replacement for LP3961ESX-3.3?

A: Yes. LP3961ESX-3.3/NOPB is the direct equivalent with identical electrical specifications, output voltage (3.3V), output current (800mA), voltage dropout (0.35V @ 800mA), package type (TO-263 DDPAK-5), and protection features. The primary differences are product status (Active vs. Obsolete) and RoHS compliance level.

Q: What is the difference between LP3871ESX-3.3/NOPB and LP3964ESX-3.3/NOPB?

A: Both parts are parametric equivalents with identical output voltage (3.3V), output current (800mA), and package specifications. The key difference is quiescent current: LP3871ESX-3.3/NOPB operates at 5mA while LP3964ESX-3.3/NOPB operates at 9mA. LP3871ESX-3.3/NOPB is preferred for applications prioritizing low standby power consumption.

Q: Are all substitute parts compatible with the same PCB layout?

A: Yes. All substitute parts use the identical TO-263 (DDPAK-5) package with the same pinout, mechanical dimensions, and thermal characteristics, enabling direct PCB layout compatibility without redesign.

Q: What is the MSL rating and why does it matter?

A: All parts carry MSL 3 (168 Hours) rating, indicating moisture sensitivity level 3 with a floor life of 168 hours after bag opening. This requires standard moisture control procedures during storage and assembly to prevent solder joint reliability issues.

Q: Are there any performance differences between the substitute parts?

A: All substitute parts maintain identical output voltage (3.3V), output current (800mA), voltage dropout (0.35V @ 800mA), and protection features. LP3871ESX-3.3/NOPB features lower quiescent current (5mA vs. 9mA), which reduces standby power consumption. LP3871ESX-3.3/NOPB also specifies PSRR performance (73dB ~ 57dB at 120Hz), while other parts do not provide this specification.

Q: Which substitute part should be selected for new designs?

A: LP3961ESX-3.3/NOPB is the primary recommendation for new designs due to direct equivalence and Active product status. For applications requiring enhanced power efficiency or PSRR performance, LP3871ESX-3.3/NOPB is an appropriate alternative.