LM2576T-3.3/LB03 Equivalent & Substitute Parts

Part Overview

The LM2576T-3.3/LB03 is a buck switching regulator IC from Texas Instruments, part of the SIMPLE SWITCHER® series. It provides a fixed 3.3V output at 3A maximum current, designed for step-down voltage conversion applications with input voltage range from 4V to 40V. The device operates at 52kHz switching frequency and is housed in a TO-220-5 package with formed leads.

This part is classified as obsolete. Identifying equivalent and substitute parts is necessary to ensure design continuity, maintain supply chain reliability, and support ongoing production or maintenance requirements.

Substiute Parts

LM2576T-3.3/LB03

Texas InstrumentsIn Stock: 775LM2576T-3.3/LB03 Datasheet

Current PartRFQ

LM2576T-3.3/NOPB

Texas InstrumentsIn Stock: 1389LM2576T-3.3/NOPB Datasheet

DirectRFQ

LM2575TV-3.3G

onsemiIn Stock: 1037LM2575TV-3.3G Datasheet

MFR RecommendedRFQ

LM2576TV-3.3G

onsemiIn Stock: 1008LM2576TV-3.3G Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LM2576T-3.3/LB03 is determined by the following critical parameters:

• Output voltage: 3.3V fixed
• Output current capability: minimum 3A
• Input voltage range: 4V to 40V minimum
• Package type: TO-220-5
• Topology: Buck (step-down)
• Switching frequency: 52kHz
• Operating temperature range: -40°C to 125°C

Substitute parts are grouped into two categories:

Direct Equivalent (Same Manufacturer): LM2576T-3.3/NOPB from Texas Instruments maintains identical electrical specifications and packaging, with the primary difference being product status (active vs. obsolete) and RoHS compliance level.

Cross-Manufacturer Substitutes: LM2576TV-3.3G and LM2575TV-3.3G from onsemi provide functional equivalence but with variations in input voltage minimum, output current capability, and product status that must be evaluated for specific application requirements.

Parameter Comparison

Engineering Selection Recommendations

LM2576T-3.3/NOPB (Texas Instruments): This is the primary substitute for the LM2576T-3.3/LB03. It maintains identical electrical and mechanical specifications while offering active product status and ROHS3 compliance. This part is recommended for new designs and ongoing production where regulatory compliance is required.

LM2576TV-3.3G (onsemi): This part provides functional equivalence with 3A output current capability and identical switching frequency. However, the minimum input voltage is 7V compared to 4V for the main part, which restricts its use in applications requiring lower input voltage operation. Product status is obsolete. This substitute is suitable only when input voltage remains above 7V.

LM2575TV-3.3G (onsemi): This part is not recommended as a direct substitute due to reduced output current capability (1A vs. 3A). While it maintains the 3.3V output voltage and 52kHz switching frequency, the lower current rating makes it unsuitable for applications requiring 3A output. The higher minimum input voltage (4.75V) further limits compatibility.

Frequently Asked Questions (FAQ)

Q: Can LM2576T-3.3/NOPB be used as a direct replacement for LM2576T-3.3/LB03?

A: Yes. Both parts share identical electrical specifications, output voltage, current rating, input voltage range, switching frequency, and package type. The primary differences are product status (active vs. obsolete) and RoHS compliance level (ROHS3 vs. non-compliant). LM2576T-3.3/NOPB is the recommended substitute.

Q: What is the key limitation of LM2576TV-3.3G as a substitute?

A: The minimum input voltage requirement is 7V, compared to 4V for the LM2576T-3.3/LB03. Applications operating with input voltages between 4V and 7V cannot use this substitute. All other electrical parameters and the TO-220-5 package remain compatible.

Q: Why is LM2575TV-3.3G not suitable as a substitute?

A: The LM2575TV-3.3G has a maximum output current of 1A, while the LM2576T-3.3/LB03 is rated for 3A. This 67% reduction in current capacity makes it incompatible with applications requiring the full 3A output specification.

Q: Are all substitute parts available in the same TO-220-5 package?

A: Yes. All listed substitute parts use the TO-220-5 package with formed leads, ensuring mechanical and thermal compatibility with existing PCB designs and thermal management solutions.

Q: What compliance considerations apply when selecting a substitute?

A: The LM2576T-3.3/NOPB is ROHS3 compliant, while the main part and onsemi substitutes are either non-compliant or have not applicable MSL ratings. For applications subject to RoHS regulations, LM2576T-3.3/NOPB is the appropriate choice.