LM2575T-3.3 Buck Switching Regulator Equivalent & Substitute Parts

Part Overview

The LM2575T-3.3 is a buck switching regulator IC from Texas Instruments, part of the SIMPLE SWITCHER® series. It provides a fixed 3.3V output at 1A from input voltages ranging from 4V to 40V, operating across the industrial temperature range of -40°C to 125°C. The main part is currently listed as obsolete, making equivalent and substitute parts necessary for ongoing design support and production continuity.

Substiute Parts

LM2575T-3.3

Texas InstrumentsIn Stock: 88993LM2575T-3.3 Datasheet

Current PartRFQ

LM2575T-3.3/LF03

Texas InstrumentsIn Stock: 1242LM2575T-3.3/LF03 Datasheet

DirectRFQ

LM2575T-3.3/NOPB

Texas InstrumentsIn Stock: 6228LM2575T-3.3/NOPB Datasheet

DirectRFQ

LM2575T-3.3G

onsemiIn Stock: 1543LM2575T-3.3G Datasheet

MFR RecommendedRFQ

LM2576-3.3WT

Microchip TechnologyIn Stock: 4132LM2576-3.3WT Datasheet

MFR RecommendedRFQ

LM2576T-3.3G

onsemiIn Stock: 3270LM2576T-3.3G Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the LM2575T-3.3 is determined by the following critical parameters: fixed 3.3V output voltage, buck topology, TO-220-5 package, through-hole mounting, and operating temperature range of -40°C to 125°C. Parts are grouped into two categories based on output current capability and product status.

Category 1: Direct Equivalents (1A Output) Parts maintaining the original 1A output current specification with identical electrical characteristics and packaging.

Category 2: Higher Current Alternatives (3A Output) Parts with increased output current capability (3A) that provide enhanced performance headroom while maintaining the same voltage, topology, package, and temperature range. These are suitable for applications where the original 1A specification is marginal or where future design flexibility is required.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (1A Applications): LM2575T-3.3/NOPB from Texas Instruments is the primary recommended substitute. It maintains identical electrical specifications and packaging while offering active product status and ROHS3 compliance. This part provides the most direct functional equivalence with superior supply chain availability (6200 pcs in stock).

LM2575T-3.3/LF03 is an alternative from Texas Instruments with formed leads packaging, suitable for applications requiring specific lead geometry. Both Texas Instruments variants ensure design continuity with the original part.

LM2575T-3.3G from onsemi provides an active alternative with identical output current and package. Note the minimum input voltage is 4.75V versus 4V for the original specification. This part is suitable for applications where the input voltage floor exceeds 4.75V.

For Enhanced Performance (3A Applications): LM2576-3.3WT from Microchip Technology offers triple the output current (3A) while maintaining the same voltage, topology, package, and temperature range. This part is recommended for applications requiring increased current capacity or design margin. It maintains the 4V minimum input voltage specification.

LM2576T-3.3G from onsemi provides 3A output capability with active product status. The minimum input voltage requirement is 7V, making this suitable only for applications with higher input voltage floors.

Compliance Considerations: All recommended substitutes are ROHS3 compliant, addressing environmental and regulatory requirements. The original LM2575T-3.3 is RoHS non-compliant; migration to compliant alternatives is necessary for new designs and ongoing production.

Frequently Asked Questions (FAQ)

Q: Can LM2575T-3.3/NOPB be used as a direct drop-in replacement for LM2575T-3.3? A: Yes. Both parts share identical electrical specifications (3.3V output, 1A current, 4V to 40V input range, 52kHz switching frequency) and TO-220-5 packaging. The primary differences are product status (active versus obsolete) and RoHS compliance (ROHS3 versus non-compliant). No circuit modifications are required.

Q: What is the difference between LM2575T-3.3/LF03 and LM2575T-3.3/NOPB? A: Both are Texas Instruments LM2575T-3.3 variants with identical electrical performance. The difference is packaging: LF03 specifies formed leads, while NOPB uses standard leads. Selection depends on PCB lead hole specifications and assembly equipment compatibility.

Q: Can I use LM2576-3.3WT instead of LM2575T-3.3? A: Yes, with design considerations. The LM2576-3.3WT provides 3A output versus the original 1A specification, maintaining the same 3.3V output, input voltage range (4V to 40V), package, and temperature range. This substitution is suitable for applications requiring higher current capacity. No circuit modifications are necessary, though thermal management may improve due to lower output impedance.

Q: What is the minimum input voltage requirement for LM2575T-3.3G from onsemi? A: The onsemi LM2575T-3.3G specifies a minimum input voltage of 4.75V, compared to 4V for the Texas Instruments original. This part is suitable only for applications where the input voltage remains above 4.75V throughout operation.

Q: Why is LM2576T-3.3G listed as obsolete if it is a substitute? A: LM2576T-3.3G from onsemi is included as a documented substitute option but carries obsolete product status. For new designs, LM2576-3.3WT from Microchip Technology is the recommended 3A alternative due to active product status and superior availability.

Q: Are all substitute parts RoHS compliant? A: Yes. All recommended substitute parts carry ROHS3 compliance status. The original LM2575T-3.3 is RoHS non-compliant. Migration to compliant alternatives is necessary for regulatory adherence in new production.

Q: Can I use a 3A part in a 1A application? A: Yes. The LM2576-3.3WT and LM2576T-3.3G are rated for 3A output but can operate at lower currents. The application will function correctly at 1A or below. This approach provides design margin and thermal headroom.