LP3873ESX-1.8 Linear Voltage Regulator IC Equivalent & Substitute Parts

Part Overview

The LP3873ESX-1.8 is a linear voltage regulator IC from Texas Instruments, classified as a Power Management (PMIC) component. This device delivers a fixed 1.8V output at 3A maximum current in a TO-263 (DDPAK-5) surface mount package. The part is currently listed as obsolete, making identification of equivalent and substitute components essential for design continuity and procurement planning. Substitute parts must maintain identical electrical performance characteristics and mechanical compatibility to ensure direct replacement capability in existing circuit designs.

Substiute Parts

LP3873ESX-1.8

Texas InstrumentsIn Stock: 1849LP3873ESX-1.8 Datasheet

Current PartRFQ

LP3873ESX-1.8/NOPB

National SemiconductorIn Stock: 4042LP3873ESX-1.8/NOPB Datasheet

DirectRFQ

LP3853ESX-1.8/NOPB

Texas InstrumentsIn Stock: 868LP3853ESX-1.8/NOPB Datasheet

Parametric EquivalentRFQ

LP3856ESX-1.8/NOPB

Texas InstrumentsIn Stock: 2148LP3856ESX-1.8/NOPB Datasheet

Parametric EquivalentRFQ

LP3876ESX-1.8/NOPB

Texas InstrumentsIn Stock: 1441LP3876ESX-1.8/NOPB Datasheet

Parametric EquivalentRFQ

LP3966ESX-1.8

Texas InstrumentsIn Stock: 3950LP3966ESX-1.8 Datasheet

Parametric EquivalentRFQ

LP3966ESX-1.8/NOPB

Texas InstrumentsIn Stock: 1638LP3966ESX-1.8/NOPB Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the LP3873ESX-1.8 are classified based on electrical parameter compatibility and product status. The primary substitution criteria are:

Critical Parameters for Substitution:

• Output voltage: 1.8V fixed
• Output current capability: 3A
• Input voltage rating: 7V maximum
• Package type: TO-263 (DDPAK-5)
• Operating temperature range: -40°C ~ 125°C
• Protection features: Over Current, Over Temperature, Short Circuit

Substitution Categories:

Direct Manufacturer Equivalent: LP3873ESX-1.8/NOPB maintains identical electrical specifications and is supplied by National Semiconductor with bulk packaging.

Parametric Equivalents with Improved Performance: LP3853ESX-1.8/NOPB and LP3856ESX-1.8/NOPB offer superior dropout voltage performance (0.6V @ 3A versus 1.2V @ 3A) and reduced quiescent current (4 mA versus 9 mA), while maintaining all other critical parameters.

Parametric Equivalents with Standard Performance: LP3876ESX-1.8/NOPB, LP3966ESX-1.8, and LP3966ESX-1.8/NOPB maintain the original dropout voltage and quiescent current specifications with minor variations in supply current and PSRR characteristics.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement with Active Product Status: LP3873ESX-1.8/NOPB is the primary direct equivalent, maintaining identical electrical specifications while offering active product status. This part is suitable for applications requiring exact parameter matching to the obsolete LP3873ESX-1.8.

For Improved Efficiency and Reduced Power Dissipation: LP3853ESX-1.8/NOPB and LP3856ESX-1.8/NOPB are recommended for new designs or redesigns where lower dropout voltage (0.6V versus 1.2V) and reduced quiescent current (4 mA versus 9 mA) provide measurable power efficiency gains. Both parts are ROHS3 compliant and actively supported.

For RoHS3 Compliance with Maintained Original Specifications: LP3876ESX-1.8/NOPB and LP3966ESX-1.8/NOPB maintain the original dropout voltage and quiescent current characteristics while offering ROHS3 compliance. LP3966ESX-1.8/NOPB is preferred due to active product status, while LP3966ESX-1.8 is available but designated as Last Time Buy.

Packaging and Certification Considerations: All substitute parts are supplied in TO-263 (DDPAK-5) surface mount packages with identical mechanical dimensions. LP3853ESX-1.8/NOPB and LP3856ESX-1.8/NOPB carry REACH Affected and REACH Unaffected designations respectively. All parts maintain MSL 3 (168 Hours) moisture sensitivity rating.

Frequently Asked Questions (FAQ)

Q: Can LP3853ESX-1.8/NOPB be used as a direct replacement for LP3873ESX-1.8?

A: Yes, LP3853ESX-1.8/NOPB is electrically compatible and mechanically interchangeable. The lower dropout voltage (0.6V versus 1.2V) and reduced quiescent current (4 mA versus 9 mA) represent performance improvements that do not compromise circuit functionality. The part is ROHS3 compliant and actively supported.

Q: What is the difference between LP3873ESX-1.8/NOPB and LP3873ESX-1.8?

A: LP3873ESX-1.8/NOPB is the NOPB (No Plumbum/Lead-Free) variant supplied by National Semiconductor. Both parts maintain identical electrical specifications and TO-263 (DDPAK-5) packaging. The primary difference is manufacturer designation and product status.

Q: Are all substitute parts available in the same TO-263 (DDPAK-5) package?

A: Yes, all listed substitute parts are supplied in TO-263 (DDPAK-5) surface mount packages with identical mechanical dimensions and pinout compatibility. No PCB layout modifications are required for substitution.

Q: Which substitute part offers the best power efficiency?

A: LP3853ESX-1.8/NOPB and LP3856ESX-1.8/NOPB offer the lowest dropout voltage (0.6V @ 3A) and quiescent current (4 mA), resulting in reduced power dissipation compared to the original LP3873ESX-1.8 specification (1.2V dropout, 9 mA quiescent current).

Q: What is the significance of the /NOPB designation?

A: The /NOPB suffix indicates a lead-free (No Plumbum) variant compliant with RoHS directives. This designation is standard for modern semiconductor components and does not affect electrical performance or mechanical compatibility.

Q: Is LP3966ESX-1.8 suitable for new designs?

A: LP3966ESX-1.8 is designated as Last Time Buy, indicating limited future availability. For new designs, LP3966ESX-1.8/NOPB (active status) or LP3853ESX-1.8/NOPB and LP3856ESX-1.8/NOPB (improved performance) are recommended alternatives.

Q: What are the operating temperature specifications for all substitute parts?

A: All substitute parts maintain the original operating temperature range of -40°C to 125°C, ensuring compatibility across industrial and commercial temperature specifications.