LM2575T-3.3 Equivalent & Substitute Parts

Part Overview

The LM2575T-3.3 is a buck switching regulator IC manufactured by onsemi, delivering a fixed 3.3V output at 1A from input voltages ranging from 4.75V to 40V. This TO-220-5 package device operates at 52kHz switching frequency and is rated for -40°C to 125°C junction temperature. The part is currently obsolete, making equivalent substitutes necessary for new designs and ongoing production requirements. Substitute parts must maintain electrical compatibility across input voltage range, output voltage specification, and output current capacity while meeting modern RoHS compliance standards.

Substiute Parts

LM2575T-3.3

onsemiIn Stock: 88963LM2575T-3.3 Datasheet

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LM2575T-3.3G

onsemiIn Stock: 1543LM2575T-3.3G Datasheet

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AP1501-33T5L-U

Diodes IncorporatedIn Stock: 1952AP1501-33T5L-U Datasheet

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LM2576-3.3WT

Microchip TechnologyIn Stock: 4132LM2576-3.3WT Datasheet

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LM2591HVT-3.3/NOPB

Texas InstrumentsIn Stock: 2169LM2591HVT-3.3/NOPB Datasheet

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LM2596T-3.3/NOPB

Texas InstrumentsIn Stock: 4142LM2596T-3.3/NOPB Datasheet

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MIC4575-3.3WT

Microchip TechnologyIn Stock: 4220MIC4575-3.3WT Datasheet

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MIC4576-3.3WT

Microchip TechnologyIn Stock: 3727MIC4576-3.3WT Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution for the LM2575T-3.3 is determined by the following critical parameters:

Primary Substitution Criteria:

• Output voltage: 3.3V fixed
• Package type: TO-220-5 through-hole mounting
• Topology: Buck (step-down) switching regulator
• Output current capability: minimum 1A
• Input voltage range: must accommodate 4.75V to 40V minimum
• Operating temperature range: -40°C to 125°C minimum

Substitution Categories:

Direct Equivalent (Identical Specifications): LM2575T-3.3G maintains the exact electrical specifications of the original part with identical 1A output current, 52kHz switching frequency, and 4.75V to 40V input range. This part differs only in product status (Active vs. Obsolete) and RoHS compliance (ROHS3 Compliant).

Higher Current Capacity Substitutes: LM2596T-3.3/NOPB, LM2576-3.3WT, MIC4576-3.3WT, and AP1501-33T5L-U provide 3A output current capability in the same TO-220-5 package. These parts are suitable for applications where the original 1A specification is insufficient, provided circuit design accommodates the higher current rating.

Alternative Topology Substitute: MIC4575-3.3WT combines buck and buck-boost topologies with 1.7A switch current, offering functional flexibility beyond the original buck-only design.

Higher Input Voltage Tolerance: LM2591HVT-3.3/NOPB extends maximum input voltage to 60V while maintaining 1A output current, suitable for applications requiring extended input voltage range.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Identical Electrical Performance): LM2575T-3.3G is the primary substitute, offering identical electrical specifications with the advantage of Active product status and ROHS3 compliance. This part is recommended for applications requiring no design modification.

For Applications Requiring Higher Output Current: LM2596T-3.3/NOPB and LM2576-3.3WT both provide 3A output current in the same TO-220-5 package. LM2576-3.3WT maintains the original 52kHz switching frequency, while LM2596T-3.3/NOPB operates at 150kHz. Both are ROHS3 compliant and rated to -40°C to 125°C.

For Extended Input Voltage Range Applications: LM2591HVT-3.3/NOPB supports input voltages up to 60V compared to the original 40V maximum, with maintained 1A output current and -40°C to 125°C operating range. This part is suitable for applications with variable or elevated input voltage sources.

For Switching Frequency Considerations: Original 52kHz operation is preserved in LM2575T-3.3G and LM2576-3.3WT. Higher switching frequencies (150kHz in Texas Instruments parts, 200kHz in Microchip MIC45xx series) reduce output filter component size but may require circuit design verification.

For Temperature-Constrained Applications: MIC4575-3.3WT and MIC4576-3.3WT operate to -40°C to 85°C maximum, which is 40°C lower than the original specification. These parts are not suitable for applications requiring full -40°C to 125°C range.

Compliance Consideration: All recommended substitutes are ROHS3 compliant and REACH unaffected, addressing the non-compliance status of the obsolete LM2575T-3.3.

Frequently Asked Questions (FAQ)

Q: Can LM2575T-3.3G be used as a direct drop-in replacement? A: Yes. LM2575T-3.3G maintains identical electrical specifications including 1A output current, 52kHz switching frequency, 4.75V to 40V input range, and TO-220-5 package. No circuit design changes are required.

Q: What is the difference between 1A and 3A output current substitutes? A: The original LM2575T-3.3 is rated for 1A maximum output current. Higher-rated substitutes (LM2596T-3.3/NOPB, LM2576-3.3WT, MIC4576-3.3WT at 3A) can supply greater load current. Circuit design must ensure load current does not exceed the original 1A specification unless the application is redesigned to utilize the higher capability.

Q: Does switching frequency affect circuit compatibility? A: Switching frequency affects output filter design and EMI characteristics. The original 52kHz is maintained in LM2575T-3.3G and LM2576-3.3WT. Higher frequencies (150kHz, 200kHz) allow smaller filter components but require verification that existing filter designs remain effective.

Q: Are all substitutes available in the same package? A: All recommended substitutes use TO-220-5 through-hole package with identical pinout compatibility. AP1501-33T5L-U uses TO-220-5L variant, which maintains mechanical and electrical compatibility.

Q: What is the significance of ROHS3 compliance? A: ROHS3 compliance indicates the part meets current Restriction of Hazardous Substances regulations. The original LM2575T-3.3 is RoHS non-compliant. All recommended substitutes are ROHS3 compliant, meeting modern procurement and environmental standards.

Q: Can MIC4575-3.3WT be used in place of the original part? A: MIC4575-3.3WT provides buck and buck-boost topology with 1.7A switch current and 200kHz switching frequency. The reduced maximum operating temperature (-40°C to 85°C vs. -40°C to 125°C) and lower maximum input voltage (24V vs. 40V) restrict its use to applications within these limits.

Q: What input voltage range should be verified when substituting? A: The original part operates from 4.75V to 40V. Most substitutes maintain this range or extend it. MIC4575-3.3WT has a reduced maximum of 24V. Verify the substitute's input voltage range accommodates your application's supply voltage variation.