LM2937ET-3.3 Equivalent & Substitute Parts

Part Overview

The LM2937ET-3.3 is a linear voltage regulator IC from Texas Instruments, classified as a Power Management (PMIC) component. It delivers a fixed positive 3.3V output at 500mA in a TO-220-3 through-hole package. The device is currently in Last Time Buy status, indicating end-of-life production. Finding equivalent and substitute parts ensures design continuity and supply chain reliability for applications requiring 3.3V regulation in this form factor.

Substiute Parts

LM2937ET-3.3

Texas InstrumentsIn Stock: 3342LM2937ET-3.3 Datasheet

Current PartRFQ

LM2937ET-3.3/NOPB

Texas InstrumentsIn Stock: 2144LM2937ET-3.3/NOPB Datasheet

DirectRFQ

MIC29150-3.3WT

Microchip TechnologyIn Stock: 5421MIC29150-3.3WT Datasheet

MFR RecommendedRFQ

MIC2920A-3.3WT

Microchip TechnologyIn Stock: 9664MIC2920A-3.3WT Datasheet

MFR RecommendedRFQ

MIC29300-3.3WT

Microchip TechnologyIn Stock: 4481MIC29300-3.3WT Datasheet

MFR RecommendedRFQ

MIC2937A-3.3WT

Microchip TechnologyIn Stock: 1166MIC2937A-3.3WT Datasheet

MFR RecommendedRFQ

MIC2940A-3.3WT

Microchip TechnologyIn Stock: 9401MIC2940A-3.3WT Datasheet

MFR RecommendedRFQ

MIC29500-3.3WT

Microchip TechnologyIn Stock: 2871MIC29500-3.3WT Datasheet

MFR RecommendedRFQ

TC1262-3.3VAB

Microchip TechnologyIn Stock: 9380TC1262-3.3VAB Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LM2937ET-3.3 is determined by the following critical parameters:

• Fixed output voltage of 3.3V
• TO-220-3 package configuration
• Through-hole mounting type
• Operating temperature range of -40°C to 125°C
• ROHS3 compliance and REACH unaffected status

Substitute parts are grouped into two categories:

Direct Equivalent: LM2937ET-3.3/NOPB (Texas Instruments) — identical specifications with active product status.

Functional Equivalents: Microchip Technology parts (MIC series and TC1262) that maintain the same output voltage, package, and mounting type while offering varying output current ratings (400mA to 5A) and improved dropout voltage characteristics. These parts are suitable for applications where the original 500mA specification can be met by higher-rated alternatives or where lower dropout voltage is beneficial.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement: LM2937ET-3.3/NOPB is the primary choice. It maintains identical electrical specifications and is in active production status, ensuring long-term availability. Both parts are ROHS3 compliant and REACH unaffected.

For Higher Current Applications: MIC29150-3.3WT, MIC29300-3.3WT, and MIC29500-3.3WT provide 1.5A, 3A, and 5A output respectively, with improved dropout voltage (0.6V) compared to the original 1V specification. These are suitable when the application requires headroom beyond 500mA.

For Lower Current Applications: MIC2920A-3.3WT delivers 400mA with reduced dropout voltage (0.75V), appropriate for designs with tighter power budgets.

For Matched Current Rating: MIC2937A-3.3WT (750mA) and TC1262-3.3VAB (500mA) both maintain or exceed the original 500mA specification. TC1262-3.3VAB features lower quiescent current (130µA) and PSRR of 64dB at 1kHz, beneficial for noise-sensitive applications. However, TC1262-3.3VAB has a maximum input voltage of 6V, limiting its use to lower-voltage input designs compared to the 26V maximum of other options.

All substitute parts are ROHS3 compliant, REACH unaffected, and rated for -40°C to 125°C operation, matching the original device's compliance profile.

Frequently Asked Questions (FAQ)

Q: Can I use MIC29150-3.3WT as a direct replacement for LM2937ET-3.3?

A: Yes, for applications requiring up to 1.5A output. The MIC29150-3.3WT maintains the same 3.3V output, TO-220-3 package, and operating temperature range. It features superior dropout voltage (0.6V vs. 1V), making it suitable for designs where the original 500mA specification is adequate but lower dropout is beneficial. Verify your circuit's current requirements do not exceed 1.5A.

Q: What is the key difference between TC1262-3.3VAB and other substitutes?

A: TC1262-3.3VAB has a maximum input voltage of 6V, compared to 26V for all other options. This limits its application to low-voltage input designs. However, it offers lower quiescent current (130µA) and measurable PSRR (64dB at 1kHz), making it preferable for battery-powered or noise-sensitive applications operating within the 6V input constraint.

Q: Are all substitute parts pin-compatible with the original LM2937ET-3.3?

A: All substitute parts use the TO-220-3 package with identical pin configuration (Input, Ground, Output), ensuring mechanical and electrical compatibility. No PCB modifications are required for package-level substitution.

Q: Which substitute offers the best dropout voltage performance?

A: MIC29150-3.3WT, MIC29300-3.3WT, and MIC29500-3.3WT all feature 0.6V dropout voltage at their respective rated currents, compared to 1V for the original LM2937ET-3.3. MIC2940A-3.3WT also provides 0.6V dropout at 1.25A. These are optimal for designs with tight input-to-output voltage margins.

Q: Can I substitute a higher-current part like MIC29500-3.3WT in a design rated for 500mA?

A: Yes. Higher-current rated regulators are backward-compatible with lower-current applications. The MIC29500-3.3WT will deliver the required 500mA without degradation. Verify thermal management is adequate, as higher-rated devices may have different thermal characteristics.

Q: What is the inventory status of these substitutes?

A: LM2937ET-3.3/NOPB has 2,100 units in stock. Microchip alternatives have higher availability: MIC2920A-3.3WT (9,600 units), MIC2940A-3.3WT (9,300 units), TC1262-3.3VAB (9,300 units), MIC29150-3.3WT (5,400 units), MIC29300-3.3WT (4,420 units), and MIC29500-3.3WT (2,819 units). MIC2937A-3.3WT has limited stock (1,058 units).